Dag Hofsø - Academia.edu (original) (raw)

Papers by Dag Hofsø

Research paper thumbnail of Vitamin status in morbidly obese patients: a cross-sectional study1-3

Background: Morbid obesity is associated with low circulating concentrationsof25-hydroxyvitaminD.... more Background: Morbid obesity is associated with low circulating concentrationsof25-hydroxyvitaminD.Fewdataontheconcentra- tions of other vitamins in morbidly obese patients are available. Objective: The objective was to compare serum and blood vitamin concentrations in morbidly obese patients with those in healthy subjects. Design: In 2 public hospital departments (southeast Norway), we prospectively examined 110 consecutive patients (76 women) and 58 healthy controls (30

Research paper thumbnail of Dietary changes in obese patients undergoing gastric bypass or lifestyle intervention: a clinical trial

British Journal of Nutrition, 2013

We compared changes in the dietary patterns of morbidly obese patients undergoing either laparosc... more We compared changes in the dietary patterns of morbidly obese patients undergoing either laparoscopic gastric bypass surgery or a comprehensive lifestyle intervention programme. The present 1-year non-randomised controlled trial included fifty-four patients in the lifestyle group and seventy-two in the surgery group. Dietary intake was assessed by a validated FFQ. ANCOVA was used to adjust for betweengroup differences in sex, age, baseline BMI and baseline values of the dependent variables. Intakes of food groups and nutrients did not differ significantly between the intervention groups at baseline. At 1-year follow-up, the lifestyle group had a significantly higher daily intake of fruits and vegetables (561 (SD 198) v. 441 (SD 213) g, P¼ 0·002), whole grains (63 (SD 24) v. 49 (SD 16) g, P,0·001) and fibre (28 (SD 6) v. 22 (SD 6) g, P,0·001) than the surgery group and a lower percentage of total energy intake of saturated fat (12 (SD 3) v. 14 (SD 3) %, P, 0·001). The intake of red meat declined significantly within both groups, vegetables and fish intake were reduced significantly in the surgery group and added sugar was reduced significantly in the lifestyle group. The lifestyle patients improved their dietary patterns significantly (compared with the surgery group), increasing their intake of vegetables, whole grains and fibre and reducing their percentage intake of saturated fat (ANCOVA, all P,0·001). In conclusion, lifestyle intervention was associated with more favourable dietary 1-year changes than gastric bypass surgery in morbidly obese patients, as measured by intake of vegetables, whole grains, fibre and saturated fat.

Research paper thumbnail of Vitamin status after gastric bypass and lifestyle intervention: a comparative prospective study

Surgery for Obesity and Related Diseases, 2012

Background: Bariatric surgery can lead to vitamin deficiencies. We aimed to assess the changes in... more Background: Bariatric surgery can lead to vitamin deficiencies. We aimed to assess the changes in blood vitamin concentrations in patients who were taking predefined supplements after gastric bypass surgery. Methods: A total of 29 patients underwent gastric bypass and 24 unmatched controls underwent lifestyle intervention in a prospective, nonrandomized trial. The patients in the surgical group received multivitamin, iron, calcium, vitamin D, and vitamin B 12 supplements. No supplements were prescribed to the lifestyle group. The median body mass index decreased from 46 to 32 kg/m 2 after surgery and from 40 to 39 kg/m 2 after lifestyle intervention. Results: Of the 53 included patients, 50 completed the 1-year follow-up examination (94%). Compared with the lifestyle patients, the surgical patients had increased vitamin B 6 , folic acid, vitamin B 12 , and lipid-adjusted vitamin E (P Ͻ.02 for each) concentrations but decreased vitamin A concentrations (P Ͻ.01) during follow-up. No significant difference between the 2 groups was found for vitamin B 1 , vitamin C, or 25-hydroxyvitamin D. Most surgical patients reported taking their supplements. Conclusion: Gastric bypass patients adhering to a set of dietary supplements had mostly stable or increased vitamin concentrations compared with both their baseline values and the changes in a nonsurgical control group. (Surg Obes Relat Dis 2011;xx:xxx.)

Research paper thumbnail of Comparison of vitamin concentrations after gastric bypass and lifestyle intervention

Surgery for Obesity and Related Diseases, 2010

Research paper thumbnail of A controlled clinical trial of the effect of gastric bypass surgery and intensive lifestyle intervention on nocturnal hypertension and the circadian blood pressure rhythm in patients with morbid obesity

Surgery, 2012

Nocturnal hypertension, increased night-to-day systolic blood pressure (BP) ratio and nondipper s... more Nocturnal hypertension, increased night-to-day systolic blood pressure (BP) ratio and nondipper status (night-to-day systolic BP ratio > 0.9) are associated with an increased risk of cardiovascular disease. Our aim was to compare the 1-year effect of Roux-en-Y gastric bypass (RYGB) versus a program of intensive lifestyle intervention (ILI) only on nocturnal hypertension and circadian BP rhythm. The study participants were part of a 1-year, controlled clinical trial comparing the effect of RYGB or ILI on obesity-related comorbidities. Ninety participants (49 in the RYGB group) successfully completed 24-hour ambulatory BP monitoring at baseline and follow-up and were eligible subsequently for analysis. A total of 71 subjects (79%) had nocturnal hypertension at baseline. The number of subjects with nocturnal hypertension decreased from 42 to 14 in the RYGB group (P ≤ .001) and from 29 to 27 (P = .791) in the ILI group. Subjects in the RYGB group had a lesser adjusted odds ratio (OR) of nocturnal hypertension at follow-up (OR 0.15; 95% confidence interval, 0.05-0.42; P ≤ .001); however, after further adjustment for weight loss, there was no additional beneficial effect of RYGB (P = .674). No differences between groups regarding improvement in the night-to-day systolic BP ratio were found after adjustment for 24-hour systolic pressure (P = .107). Both interventions showed a decrease in the proportion of subjects classified as nondippers, namely, 44% (P ≤ .001) and 28% (P = .002) in the RYGB and ILI groups, respectively. Only RYGB was associated with a decrease in the prevalence of nocturnal hypertension. Both interventions showed an improvement in dipper status, although RYGB was more effective.

Research paper thumbnail of Morbidly Obese Patients—Who Undergoes Bariatric Surgery?

Obesity Surgery, 2010

Background Bariatric surgery particularly benefits patients with obesity-related comorbidities su... more Background Bariatric surgery particularly benefits patients with obesity-related comorbidities such as type 2 diabetes and obstructive sleep apnea. We aimed to examine whether the variables that influence treatment choice differ between morbidly obese patients undergoing bariatric surgery and those opting for conservative treatments. Methods A total of 505 consecutive morbidly obese patients (72% women; mean (SD) age 42 (12) years) who attended our tertiary care center between December 2005 and February 2007 were examined by a multidisciplinary team and offered surgical or conservative treatment. The chi-square test, independent samples t test, and multiple logistic regression were used in the statistical analyses. Results A total of 249 (49%) patients underwent bariatric surgery. When compared to the conservative group of patients, the surgery group was characterized by a significantly higher mean (SD) BMI (46.5(6.2) vs. 43.2(5.5) kg/m 2 , p<0.001), earlier onset of obesity (40% vs. 26% before 12 years of age, p<0.001), and lower age (41(11) vs. 44 (13) years, p=0.002). In contrast, the groups did not differ significantly with respect to gender or obesity-related comorbidities. After adjustments for gender, age, onset of obesity, and the number of comorbidities, multiple regression revealed that patients with BMI 40-50 or >50 kg/m 2 had between 3 (OR=3.0; 95% CI 1.9-4.9, p<0.001) and 6 (OR=5.7; 95% CI 3.0-11.0, p<0.001) times the chance of undergoing bariatric surgery when compared to patients with a BMI <40 kg/m 2 (reference).

Research paper thumbnail of Employment Is Associated with the Health-Related Quality of Life of Morbidly Obese Persons

Obesity Surgery, 2011

Background We aimed to investigate whether employment status was associated with health-related q... more Background We aimed to investigate whether employment status was associated with health-related quality of life (HRQoL) in a population of morbidly obese subjects. Methods A total of 143 treatment-seeking morbidly obese patients completed the Medical Outcome Study 36-Item Short-Form Health Survey (SF-36) and the Obesity and Weight-Loss Quality of Life (OWLQOL) questionnaires. The former (SF-36) is a generic measure of physical and mental health status and the latter (OWLQOL) an obesityspecific measure of emotional status. Multiple linear regression analyses included various measures of the HRQoL as dependent variables and employment status, education, marital status, gender, age, body mass index (BMI), type 2 diabetes, hypertension, obstructive sleep apnea, and treatment choice as independent variables. Results The patients (74% women, 56% employed) had a mean (SD, range) age of 44 (11, 19-66) years and a mean BMI of 44.3 (5.4) kg/m 2 . The employed patients reported significantly higher HRQoL scores within all eight subscales of SF-36, while the OWLQOL scores were comparable between the two groups. Multiple linear regression confirmed that employment was a strong independent predictor of HRQoL according to the SF-36. Based on part correlation coefficients, employment explained 16% of the variation in the physical and 9% in the mental component summaries of SF-36, while gender explained 22% of the variation in the OWLQOL scores. Conclusion Employment is associated with the physical and mental HRQoL of morbidly obese subjects, but is not associated with the emotional aspects of quality of life.

Research paper thumbnail of Fasting Plasma Glucose in the Screening for Type 2 Diabetes in Morbidly Obese Subjects

Obesity Surgery, 2010

Background Higher mortality rates among morbidly obese (BMI of ≥40 or ≥35 kg/m 2 with weight-rela... more Background Higher mortality rates among morbidly obese (BMI of ≥40 or ≥35 kg/m 2 with weight-related comorbidities) subjects are mainly explained by comorbidities such as type 2 diabetes. As bariatric surgery ameliorates diabetes, obese diabetic subjects will receive great benefits from bariatric surgery. Screening for diabetes prior to surgical referral is therefore crucial. Methods We studied 1,253 consecutively recruited (2005)(2006)(2007)(2008) morbidly obese subjects (67% women). Among subjects without known diabetes, 70% (670/961) performed an oral glucose tolerance test (OGTT). Screen-detected diabetes was defined as fasting plasma glucose (fPG) ≥7.0 mmol/l and/or 2-h glucose concentration (2hPG) ≥ 11.1 mmol/l. Results Within the study population, 31% had diabetes, of which 8% were screen-detected. Eighty percent of those with screen-detected diabetes were diagnosed by fPG. In subjects with nondiabetic fPG concentrations, elevating the fPG cutoff value from 5.2 mmol/l to the World Health Organization's (WHO's) recommended value of 6.1 mmol/l reduced the percentage of the population needing an OGTT considerably (78-23%), but only slightly reduced the sensitivity of fPG in detecting a diabetic 2hPG concentration (100-77%). Only 7% of the patients with fPG between 6.1 and 6.9 mmol/l had a diabetic 2hPG concentration. Following the WHO's recommendations, we found that 95% of all subjects with unknown diabetes were identified. Conclusions Fasting glucose identified four out of five morbidly obese subjects with unknown diabetes. A supplemental OGTT in selected persons identified the majority of the remaining diabetic cases.

Research paper thumbnail of Peripheral Neuropathy and Severe Malnutrition following Duodenal Switch

Obesity Surgery, 2008

Severe thiamine (vitamin B-1) deficiency is a medical emergency that has long been recognized as ... more Severe thiamine (vitamin B-1) deficiency is a medical emergency that has long been recognized as a potential complication of bariatric surgery. The incidence of this rare complication is largely unknown. We describe a super-obese male patient with extreme lower limb weakness 3 months following a duodenal switch operation, occurring in association with persisting vomiting. Excessive malabsorption led to severe malnutrition, with lower limb edemas and clinical evidence of ascites and pleural effusion. Blood tests revealed low levels of albumin, hemoglobin, potassium, vitamins A, B-1, and B-6, and elevated prothrombin time. The symptoms of neuropathy improved after extensive nutritional therapy. Weight eventually stabilized following elongation of the common channel. This case report demonstrates the importance of awareness of neurological complications following bariatric surgery. These complications require urgent and vigorous therapy when they occur.

Research paper thumbnail of Impact of gender on vitamin D deficiency in morbidly obese patients: a cross-sectional study

European Journal of Clinical Nutrition, 2012

Background/Objective: Obesity is associated with vitamin D deficiency (25-hydroxyvitamin D (25(OH... more Background/Objective: Obesity is associated with vitamin D deficiency (25-hydroxyvitamin D (25(OH)D) o50 nmol/l). We aimed to examine the effect of gender on vitamin D status in severe obesity. Subjects/Methods: Cross-sectional study of 2026 morbidly obese patients examined consecutively at a tertiary care centre between November 2005 and June 2010. Serum 25(OH)D concentration and use of vitamin D supplements were registered in all patients. Total vitamin D intake (mg/day) was assessed in a subgroup of 154 patients using a validated food frequency questionnaire. Results: The male (n ¼ 690) and female (n ¼ 1336) patients had a mean (s.d.) age of 45.0 (12.1) years and 42.2 (12.2) years (Po0.001), body mass index (BMI) of 44.6 (6.0) kg/m 2 and 44.3 (5.9) kg/m 2 (P ¼ 0.30) and waist circumference (WC) of 140 (13) cm and 127 (13) cm (Po0.001), respectively. Male patients had significantly lower mean 25(OH)D concentrations than female patients 50.0 (22.0) nmol/l versus 53.6 (22.4) nmol/l (P ¼ 0.001) and a higher rate of vitamin D deficiency (56% versus 47%; Po0.001). Obese men had significantly higher odds of vitamin D deficiency than women (odds ratio ¼ 1.41; 95% confidence interval: 1.17-1.70, Po0.001), also after adjustment for season, age, current smoking, intake of vitamin D supplements, BMI and WC (odds ratio ¼ 1.39; 95% confidence interval: 1.10-1.76). Conclusions: Morbidly obese Norwegian men seeking weight loss treatment have significantly higher odds of vitamin D deficiency than women. Monitoring of 25(OH)D concentrations in obese patients should therefore take gender into account.

Research paper thumbnail of Changes in erythropoietin and haemoglobin concentrations in response to saturation diving

European Journal of Applied Physiology, 2005

A reduction in haemoglobin concentration is consistently reported after deep saturation dives. Th... more A reduction in haemoglobin concentration is consistently reported after deep saturation dives. This may be due to a downregulation of erythropoietin (EPO) concentration or to a toxic effect of the hyperoxia associated with the dives resulting in an increased destruction rate of erythrocytes. In this study haemoglobin concentration, blood cell counts, serum ferritin, bilirubin, haptoglobin and EPO concentrations were measured before, during and after a 19 day saturation dive to 240 m. The partial pressure of oxygen (PO(2)) was 35-70 kPa during the 7 day compression and bottom phase, and 30-50 kPa during the 12 day decompression phase. There was a reduction in EPO concentration from 8.4+/-1.4 (mean +/- 1SD) to 6.3 +/- 1.9 U.L(-1) on Dive day 2. On Dive days 7 and 17 EPO concentrations were not significantly different from baseline despite the continued exposure to hyperoxia. Immediately after the dive and return to a normoxic environment there was an increase in the EPO concencentration to 14.5 +/- 4.7 U.L(-1). Haemoglobin concentration, erythrocyte and reticulocyte counts were decreased at the end of the dive, and there was an increase in serum ferritin. There were no changes in bilirubin or haptoglobin concentrations indicative of haemolysis. It appears that the change in PO(2), rather than the sustained exposure to a hyperoxic environment, induces the changes in the EPO concentrations and erythropoietic activity.

Research paper thumbnail of Anthropometric characteristics and type 2 diabetes in extremely obese Caucasian subjects: A cross-sectional study

Diabetes Research and Clinical Practice, 2009

Research paper thumbnail of Low serum creatinine is associated with type 2 diabetes in morbidly obese women and men: a cross-sectional study

BMC Endocrine Disorders, 2010

Background: Low skeletal muscle mass is associated with insulin resistance and metabolic syndrome... more Background: Low skeletal muscle mass is associated with insulin resistance and metabolic syndrome. Serum creatinine may serve as a surrogate marker of muscle mass, and a possible relationship between low serum creatinine and type 2 diabetes has recently been demonstrated. We aimed to validate this finding in a population of Caucasian morbidly obese subjects.

Research paper thumbnail of The relationship between various measures of obesity and arterial stiffness in morbidly obese patients

BMC Cardiovascular Disorders, 2011

Background: Obesity is associated with increased risk of cardiovascular disease. Arterial stiffne... more Background: Obesity is associated with increased risk of cardiovascular disease. Arterial stiffness assessed by carotid femoral pulse wave velocity (PWV) is an independent predictor of cardiovascular morbidity and mortality. We aimed to investigate how various measures of body composition affect arterial stiffness.

Research paper thumbnail of Parathyroid hormone, but not vitamin D, is associated with the metabolic syndrome in morbidly obese women and men: a cross-sectional study

Cardiovascular Diabetology, 2009

The prevalence of vitamin D insufficiency and secondary hyperparathyroidism is high among morbidl... more The prevalence of vitamin D insufficiency and secondary hyperparathyroidism is high among morbidly obese subjects. Further, low serum levels of 25-hydroxyvitamin D (25 [OH]D) and magnesium have been associated with increased risk of the metabolic syndrome (MS), and recently, a possible link between PTH and MS has been reported. Although it is well known that the synthesis and secretion of PTH is regulated by serum levels of calcium, phosphate, magnesium and 25(OH)D, less is known about the possible clustered affiliation of these parameters with MS. We aimed to explore whether MS is associated with abnormal serum levels of PTH, 25(OH)D and magnesium in a population of morbidly obese patients.

Research paper thumbnail of Vitamin status in morbidly obese patients: a cross-sectional study1-3

Background: Morbid obesity is associated with low circulating concentrationsof25-hydroxyvitaminD.... more Background: Morbid obesity is associated with low circulating concentrationsof25-hydroxyvitaminD.Fewdataontheconcentra- tions of other vitamins in morbidly obese patients are available. Objective: The objective was to compare serum and blood vitamin concentrations in morbidly obese patients with those in healthy subjects. Design: In 2 public hospital departments (southeast Norway), we prospectively examined 110 consecutive patients (76 women) and 58 healthy controls (30

Research paper thumbnail of Dietary changes in obese patients undergoing gastric bypass or lifestyle intervention: a clinical trial

British Journal of Nutrition, 2013

We compared changes in the dietary patterns of morbidly obese patients undergoing either laparosc... more We compared changes in the dietary patterns of morbidly obese patients undergoing either laparoscopic gastric bypass surgery or a comprehensive lifestyle intervention programme. The present 1-year non-randomised controlled trial included fifty-four patients in the lifestyle group and seventy-two in the surgery group. Dietary intake was assessed by a validated FFQ. ANCOVA was used to adjust for betweengroup differences in sex, age, baseline BMI and baseline values of the dependent variables. Intakes of food groups and nutrients did not differ significantly between the intervention groups at baseline. At 1-year follow-up, the lifestyle group had a significantly higher daily intake of fruits and vegetables (561 (SD 198) v. 441 (SD 213) g, P¼ 0·002), whole grains (63 (SD 24) v. 49 (SD 16) g, P,0·001) and fibre (28 (SD 6) v. 22 (SD 6) g, P,0·001) than the surgery group and a lower percentage of total energy intake of saturated fat (12 (SD 3) v. 14 (SD 3) %, P, 0·001). The intake of red meat declined significantly within both groups, vegetables and fish intake were reduced significantly in the surgery group and added sugar was reduced significantly in the lifestyle group. The lifestyle patients improved their dietary patterns significantly (compared with the surgery group), increasing their intake of vegetables, whole grains and fibre and reducing their percentage intake of saturated fat (ANCOVA, all P,0·001). In conclusion, lifestyle intervention was associated with more favourable dietary 1-year changes than gastric bypass surgery in morbidly obese patients, as measured by intake of vegetables, whole grains, fibre and saturated fat.

Research paper thumbnail of Vitamin status after gastric bypass and lifestyle intervention: a comparative prospective study

Surgery for Obesity and Related Diseases, 2012

Background: Bariatric surgery can lead to vitamin deficiencies. We aimed to assess the changes in... more Background: Bariatric surgery can lead to vitamin deficiencies. We aimed to assess the changes in blood vitamin concentrations in patients who were taking predefined supplements after gastric bypass surgery. Methods: A total of 29 patients underwent gastric bypass and 24 unmatched controls underwent lifestyle intervention in a prospective, nonrandomized trial. The patients in the surgical group received multivitamin, iron, calcium, vitamin D, and vitamin B 12 supplements. No supplements were prescribed to the lifestyle group. The median body mass index decreased from 46 to 32 kg/m 2 after surgery and from 40 to 39 kg/m 2 after lifestyle intervention. Results: Of the 53 included patients, 50 completed the 1-year follow-up examination (94%). Compared with the lifestyle patients, the surgical patients had increased vitamin B 6 , folic acid, vitamin B 12 , and lipid-adjusted vitamin E (P Ͻ.02 for each) concentrations but decreased vitamin A concentrations (P Ͻ.01) during follow-up. No significant difference between the 2 groups was found for vitamin B 1 , vitamin C, or 25-hydroxyvitamin D. Most surgical patients reported taking their supplements. Conclusion: Gastric bypass patients adhering to a set of dietary supplements had mostly stable or increased vitamin concentrations compared with both their baseline values and the changes in a nonsurgical control group. (Surg Obes Relat Dis 2011;xx:xxx.)

Research paper thumbnail of Comparison of vitamin concentrations after gastric bypass and lifestyle intervention

Surgery for Obesity and Related Diseases, 2010

Research paper thumbnail of A controlled clinical trial of the effect of gastric bypass surgery and intensive lifestyle intervention on nocturnal hypertension and the circadian blood pressure rhythm in patients with morbid obesity

Surgery, 2012

Nocturnal hypertension, increased night-to-day systolic blood pressure (BP) ratio and nondipper s... more Nocturnal hypertension, increased night-to-day systolic blood pressure (BP) ratio and nondipper status (night-to-day systolic BP ratio &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.9) are associated with an increased risk of cardiovascular disease. Our aim was to compare the 1-year effect of Roux-en-Y gastric bypass (RYGB) versus a program of intensive lifestyle intervention (ILI) only on nocturnal hypertension and circadian BP rhythm. The study participants were part of a 1-year, controlled clinical trial comparing the effect of RYGB or ILI on obesity-related comorbidities. Ninety participants (49 in the RYGB group) successfully completed 24-hour ambulatory BP monitoring at baseline and follow-up and were eligible subsequently for analysis. A total of 71 subjects (79%) had nocturnal hypertension at baseline. The number of subjects with nocturnal hypertension decreased from 42 to 14 in the RYGB group (P ≤ .001) and from 29 to 27 (P = .791) in the ILI group. Subjects in the RYGB group had a lesser adjusted odds ratio (OR) of nocturnal hypertension at follow-up (OR 0.15; 95% confidence interval, 0.05-0.42; P ≤ .001); however, after further adjustment for weight loss, there was no additional beneficial effect of RYGB (P = .674). No differences between groups regarding improvement in the night-to-day systolic BP ratio were found after adjustment for 24-hour systolic pressure (P = .107). Both interventions showed a decrease in the proportion of subjects classified as nondippers, namely, 44% (P ≤ .001) and 28% (P = .002) in the RYGB and ILI groups, respectively. Only RYGB was associated with a decrease in the prevalence of nocturnal hypertension. Both interventions showed an improvement in dipper status, although RYGB was more effective.

Research paper thumbnail of Morbidly Obese Patients—Who Undergoes Bariatric Surgery?

Obesity Surgery, 2010

Background Bariatric surgery particularly benefits patients with obesity-related comorbidities su... more Background Bariatric surgery particularly benefits patients with obesity-related comorbidities such as type 2 diabetes and obstructive sleep apnea. We aimed to examine whether the variables that influence treatment choice differ between morbidly obese patients undergoing bariatric surgery and those opting for conservative treatments. Methods A total of 505 consecutive morbidly obese patients (72% women; mean (SD) age 42 (12) years) who attended our tertiary care center between December 2005 and February 2007 were examined by a multidisciplinary team and offered surgical or conservative treatment. The chi-square test, independent samples t test, and multiple logistic regression were used in the statistical analyses. Results A total of 249 (49%) patients underwent bariatric surgery. When compared to the conservative group of patients, the surgery group was characterized by a significantly higher mean (SD) BMI (46.5(6.2) vs. 43.2(5.5) kg/m 2 , p<0.001), earlier onset of obesity (40% vs. 26% before 12 years of age, p<0.001), and lower age (41(11) vs. 44 (13) years, p=0.002). In contrast, the groups did not differ significantly with respect to gender or obesity-related comorbidities. After adjustments for gender, age, onset of obesity, and the number of comorbidities, multiple regression revealed that patients with BMI 40-50 or >50 kg/m 2 had between 3 (OR=3.0; 95% CI 1.9-4.9, p<0.001) and 6 (OR=5.7; 95% CI 3.0-11.0, p<0.001) times the chance of undergoing bariatric surgery when compared to patients with a BMI <40 kg/m 2 (reference).

Research paper thumbnail of Employment Is Associated with the Health-Related Quality of Life of Morbidly Obese Persons

Obesity Surgery, 2011

Background We aimed to investigate whether employment status was associated with health-related q... more Background We aimed to investigate whether employment status was associated with health-related quality of life (HRQoL) in a population of morbidly obese subjects. Methods A total of 143 treatment-seeking morbidly obese patients completed the Medical Outcome Study 36-Item Short-Form Health Survey (SF-36) and the Obesity and Weight-Loss Quality of Life (OWLQOL) questionnaires. The former (SF-36) is a generic measure of physical and mental health status and the latter (OWLQOL) an obesityspecific measure of emotional status. Multiple linear regression analyses included various measures of the HRQoL as dependent variables and employment status, education, marital status, gender, age, body mass index (BMI), type 2 diabetes, hypertension, obstructive sleep apnea, and treatment choice as independent variables. Results The patients (74% women, 56% employed) had a mean (SD, range) age of 44 (11, 19-66) years and a mean BMI of 44.3 (5.4) kg/m 2 . The employed patients reported significantly higher HRQoL scores within all eight subscales of SF-36, while the OWLQOL scores were comparable between the two groups. Multiple linear regression confirmed that employment was a strong independent predictor of HRQoL according to the SF-36. Based on part correlation coefficients, employment explained 16% of the variation in the physical and 9% in the mental component summaries of SF-36, while gender explained 22% of the variation in the OWLQOL scores. Conclusion Employment is associated with the physical and mental HRQoL of morbidly obese subjects, but is not associated with the emotional aspects of quality of life.

Research paper thumbnail of Fasting Plasma Glucose in the Screening for Type 2 Diabetes in Morbidly Obese Subjects

Obesity Surgery, 2010

Background Higher mortality rates among morbidly obese (BMI of ≥40 or ≥35 kg/m 2 with weight-rela... more Background Higher mortality rates among morbidly obese (BMI of ≥40 or ≥35 kg/m 2 with weight-related comorbidities) subjects are mainly explained by comorbidities such as type 2 diabetes. As bariatric surgery ameliorates diabetes, obese diabetic subjects will receive great benefits from bariatric surgery. Screening for diabetes prior to surgical referral is therefore crucial. Methods We studied 1,253 consecutively recruited (2005)(2006)(2007)(2008) morbidly obese subjects (67% women). Among subjects without known diabetes, 70% (670/961) performed an oral glucose tolerance test (OGTT). Screen-detected diabetes was defined as fasting plasma glucose (fPG) ≥7.0 mmol/l and/or 2-h glucose concentration (2hPG) ≥ 11.1 mmol/l. Results Within the study population, 31% had diabetes, of which 8% were screen-detected. Eighty percent of those with screen-detected diabetes were diagnosed by fPG. In subjects with nondiabetic fPG concentrations, elevating the fPG cutoff value from 5.2 mmol/l to the World Health Organization's (WHO's) recommended value of 6.1 mmol/l reduced the percentage of the population needing an OGTT considerably (78-23%), but only slightly reduced the sensitivity of fPG in detecting a diabetic 2hPG concentration (100-77%). Only 7% of the patients with fPG between 6.1 and 6.9 mmol/l had a diabetic 2hPG concentration. Following the WHO's recommendations, we found that 95% of all subjects with unknown diabetes were identified. Conclusions Fasting glucose identified four out of five morbidly obese subjects with unknown diabetes. A supplemental OGTT in selected persons identified the majority of the remaining diabetic cases.

Research paper thumbnail of Peripheral Neuropathy and Severe Malnutrition following Duodenal Switch

Obesity Surgery, 2008

Severe thiamine (vitamin B-1) deficiency is a medical emergency that has long been recognized as ... more Severe thiamine (vitamin B-1) deficiency is a medical emergency that has long been recognized as a potential complication of bariatric surgery. The incidence of this rare complication is largely unknown. We describe a super-obese male patient with extreme lower limb weakness 3 months following a duodenal switch operation, occurring in association with persisting vomiting. Excessive malabsorption led to severe malnutrition, with lower limb edemas and clinical evidence of ascites and pleural effusion. Blood tests revealed low levels of albumin, hemoglobin, potassium, vitamins A, B-1, and B-6, and elevated prothrombin time. The symptoms of neuropathy improved after extensive nutritional therapy. Weight eventually stabilized following elongation of the common channel. This case report demonstrates the importance of awareness of neurological complications following bariatric surgery. These complications require urgent and vigorous therapy when they occur.

Research paper thumbnail of Impact of gender on vitamin D deficiency in morbidly obese patients: a cross-sectional study

European Journal of Clinical Nutrition, 2012

Background/Objective: Obesity is associated with vitamin D deficiency (25-hydroxyvitamin D (25(OH... more Background/Objective: Obesity is associated with vitamin D deficiency (25-hydroxyvitamin D (25(OH)D) o50 nmol/l). We aimed to examine the effect of gender on vitamin D status in severe obesity. Subjects/Methods: Cross-sectional study of 2026 morbidly obese patients examined consecutively at a tertiary care centre between November 2005 and June 2010. Serum 25(OH)D concentration and use of vitamin D supplements were registered in all patients. Total vitamin D intake (mg/day) was assessed in a subgroup of 154 patients using a validated food frequency questionnaire. Results: The male (n ¼ 690) and female (n ¼ 1336) patients had a mean (s.d.) age of 45.0 (12.1) years and 42.2 (12.2) years (Po0.001), body mass index (BMI) of 44.6 (6.0) kg/m 2 and 44.3 (5.9) kg/m 2 (P ¼ 0.30) and waist circumference (WC) of 140 (13) cm and 127 (13) cm (Po0.001), respectively. Male patients had significantly lower mean 25(OH)D concentrations than female patients 50.0 (22.0) nmol/l versus 53.6 (22.4) nmol/l (P ¼ 0.001) and a higher rate of vitamin D deficiency (56% versus 47%; Po0.001). Obese men had significantly higher odds of vitamin D deficiency than women (odds ratio ¼ 1.41; 95% confidence interval: 1.17-1.70, Po0.001), also after adjustment for season, age, current smoking, intake of vitamin D supplements, BMI and WC (odds ratio ¼ 1.39; 95% confidence interval: 1.10-1.76). Conclusions: Morbidly obese Norwegian men seeking weight loss treatment have significantly higher odds of vitamin D deficiency than women. Monitoring of 25(OH)D concentrations in obese patients should therefore take gender into account.

Research paper thumbnail of Changes in erythropoietin and haemoglobin concentrations in response to saturation diving

European Journal of Applied Physiology, 2005

A reduction in haemoglobin concentration is consistently reported after deep saturation dives. Th... more A reduction in haemoglobin concentration is consistently reported after deep saturation dives. This may be due to a downregulation of erythropoietin (EPO) concentration or to a toxic effect of the hyperoxia associated with the dives resulting in an increased destruction rate of erythrocytes. In this study haemoglobin concentration, blood cell counts, serum ferritin, bilirubin, haptoglobin and EPO concentrations were measured before, during and after a 19 day saturation dive to 240 m. The partial pressure of oxygen (PO(2)) was 35-70 kPa during the 7 day compression and bottom phase, and 30-50 kPa during the 12 day decompression phase. There was a reduction in EPO concentration from 8.4+/-1.4 (mean +/- 1SD) to 6.3 +/- 1.9 U.L(-1) on Dive day 2. On Dive days 7 and 17 EPO concentrations were not significantly different from baseline despite the continued exposure to hyperoxia. Immediately after the dive and return to a normoxic environment there was an increase in the EPO concencentration to 14.5 +/- 4.7 U.L(-1). Haemoglobin concentration, erythrocyte and reticulocyte counts were decreased at the end of the dive, and there was an increase in serum ferritin. There were no changes in bilirubin or haptoglobin concentrations indicative of haemolysis. It appears that the change in PO(2), rather than the sustained exposure to a hyperoxic environment, induces the changes in the EPO concentrations and erythropoietic activity.

Research paper thumbnail of Anthropometric characteristics and type 2 diabetes in extremely obese Caucasian subjects: A cross-sectional study

Diabetes Research and Clinical Practice, 2009

Research paper thumbnail of Low serum creatinine is associated with type 2 diabetes in morbidly obese women and men: a cross-sectional study

BMC Endocrine Disorders, 2010

Background: Low skeletal muscle mass is associated with insulin resistance and metabolic syndrome... more Background: Low skeletal muscle mass is associated with insulin resistance and metabolic syndrome. Serum creatinine may serve as a surrogate marker of muscle mass, and a possible relationship between low serum creatinine and type 2 diabetes has recently been demonstrated. We aimed to validate this finding in a population of Caucasian morbidly obese subjects.

Research paper thumbnail of The relationship between various measures of obesity and arterial stiffness in morbidly obese patients

BMC Cardiovascular Disorders, 2011

Background: Obesity is associated with increased risk of cardiovascular disease. Arterial stiffne... more Background: Obesity is associated with increased risk of cardiovascular disease. Arterial stiffness assessed by carotid femoral pulse wave velocity (PWV) is an independent predictor of cardiovascular morbidity and mortality. We aimed to investigate how various measures of body composition affect arterial stiffness.

Research paper thumbnail of Parathyroid hormone, but not vitamin D, is associated with the metabolic syndrome in morbidly obese women and men: a cross-sectional study

Cardiovascular Diabetology, 2009

The prevalence of vitamin D insufficiency and secondary hyperparathyroidism is high among morbidl... more The prevalence of vitamin D insufficiency and secondary hyperparathyroidism is high among morbidly obese subjects. Further, low serum levels of 25-hydroxyvitamin D (25 [OH]D) and magnesium have been associated with increased risk of the metabolic syndrome (MS), and recently, a possible link between PTH and MS has been reported. Although it is well known that the synthesis and secretion of PTH is regulated by serum levels of calcium, phosphate, magnesium and 25(OH)D, less is known about the possible clustered affiliation of these parameters with MS. We aimed to explore whether MS is associated with abnormal serum levels of PTH, 25(OH)D and magnesium in a population of morbidly obese patients.