Long-term effects of very low-carbohydrate and high-carbohydrate weight-loss diets on psychological health in obese adults with type 2 diabetes: randomized controlled trial

BACKGROUND/OBJECTIVE

Very low-carbohydrate, high-fat (LC) diets are used for type 2 diabetes (T2DM) management, but their effects on psychological health remain largely unknown. This study examined the long-term effects of an LC diet on psychological health.

METHODS

One hundred and fifteen obese adults [age: 58.5 ± 7.1 years; body mass index: 34.6 ± 4.3 kg m(-2) ; HbA1c : 7.3 ± 1.1%] with T2DM were randomized to consume either an energy-restricted (~6 to 7 MJ), planned isocaloric LC or high-carbohydrate, low-fat (HC) diet, combined with a supervised exercise programme (3 days week(-1) ) for 1 year. Body weight, psychological mood state and well-being [Profile of Mood States (POMS), Beck Depression Inventory (BDI) and Spielberger State Anxiety Inventory (SAI)] and diabetes-specific emotional distress [Problem Areas in Diabetes (PAID) Questionnaire] and quality of life [QoL Diabetes-39 (D-39)] were assessed.

RESULTS

Overall weight loss was 9.5 ± 0.5 kg (mean ± SE), with no difference between groups (P = 0.91 time × diet). Significant improvements occurred in BDI, POMS (total mood disturbance and the six subscales of anger-hostility, confusion-bewilderment, depression-dejection, fatigue-inertia, vigour-activity and tension-anxiety), PAID (total score) and the D-39 dimensions of diabetes control, anxiety and worry, sexual functioning and energy and mobility, P < 0.05 time. SAI and the D-39 dimension of social burden remained unchanged (P ≥ 0.08 time). Diet composition had no effect on the responses for the outcomes assessed (P ≥ 0.22 time × diet).

CONCLUSION

In obese adults with T2DM, both diets achieved substantial weight loss and comparable improvements in QoL, mood state and affect. These results suggest that either an LC or HC diet within a lifestyle modification programme that includes exercise training improves psychological well-being.

Steroidal contraceptive use is associated with lower bone mineral density in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common condition affecting reproductive-aged women with features including hyperandrogenism and menstrual irregularity frequently treated with hormonal steroidal contraceptives. Women with PCOS appear to have lower bone mineral density (BMD). While steroidal contraceptives may positively affect bone health, their effect on BMD in PCOS is not known. The aim of this study was to assess BMD in women with PCOS according to recent contraceptive use. A cross-sectional analysis of 95 pre-menopausal overweight or obese sedentary women with PCOS [age 29.4 ± 6.4 years, body mass index (BMI) 36.1 ± 5.3 kg/m(2)] who either recently took steroidal contraceptives (ceased 3 months prior) or were not taking steroidal contraceptives was conducted. Clinical outcomes included BMD, anthropometry, insulin, glucose, reproductive hormones, dietary intake and vitamin use. BMD was significantly lower for women who used contraceptives compared to those who did not (mean difference 0.06 g/cm(2) 95 % confidence interval -0.11, -0.02, p = 0.005). In regression models, lower BMD was independently associated with contraceptive use (β = -0.05, 95 % CI -0.094, -0.002, p = 0.042), higher testosterone (β = -0.03, 95 % CI -0.05, -0.0008, p = 0.043) and lower BMI (β = 0.006, 95 % CI 0.002, 0.01, p = 0.007) (r (2) = 0.22, p = 0.001 for entire model). We report for the first time that overweight and obese women with PCOS with recent steroidal contraceptive use had lower BMD in comparison to non-users independent of factors known to contribute to BMD. Whether this observation is directly related to steroidal contraceptive use or other factors requires further investigation.

Short communication: a food-systems approach to assessing dairy product waste

Concern about world population increase, food security, and the environmental burdens of food production have made food-waste reduction a social and environmental priority. In this context, the quantification of dairy product waste is especially difficult due to the varied means of disposal, by solid and liquid waste streams, and due to inclusion as an ingredient in many processed foods. In this study, food intake data from the Australian National Nutrition Survey (>13,000 participants; >4,500 food items) were disaggregated into basic foods and total national dairy product intake was expressed in whole-milk equivalents. This result was compared with total domestic milk supply, indicating a level of waste of 29% for dairy products in the Australian food system. With national food-waste reduction targets becoming increasingly common, reliable estimates of food waste at the national scale are important for goal setting, baseline reporting, and performance monitoring. For this purpose, the systems approach to assessing food waste demonstrated in this project is deemed to have advantages over other common methods of food-waste assessment, such as bin audits, waste diaries, and surveys.

Sex hormone binding globulin, but not testosterone, is associated with the metabolic syndrome in overweight and obese women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with hyperandrogenism and an increased risk of Type 2 diabetes and cardiovascular disease. Decreased SHBG and elevated testosterone are associated with metabolic syndrome and glucose intolerance in women.

AIM

The aim of this study was to assess the relationship between SHBG and testosterone and metabolic syndrome and glucose intolerance in PCOS.

MATERIAL/SUBJECTS AND METHODS

Cross-sectional study in overweight and obese premenopausal non-diabetic women with PCOS (no.=178: no.=55 metabolic syndrome, no.=16 glucose intolerance). Data were analyzed by multiple regression with metabolic syndrome, oral glucose tolerance test (OGTT) glucose or SHBG as dependent variables and reproductive hormones, insulin resistance, glucose tolerance, lipids or C-reactive protein as independent variables.

RESULTS

Metabolic syndrome was independently associated with body mass index [odds ratio (OR) 1.084 95% confidence interval (CI) 1.034-1.170, p=0.015] and SHBG (OR 0.961 95% CI 0.932-0.995, p=0.018). Glucose tolerance was independently associated with OGTT insulin (β=0.418, p<0.001), age (β=0.154, p=0.033) and PRL (β=-0.210, p=0.002). SHBG was independently associated with OGTT insulin (β=-0.216, p=0.014) and PCOS diagnostic criteria (β=0.197, p=0.010).

CONCLUSIONS

SHBG, but not testosterone, is independently associated with metabolic syndrome in overweight women with PCOS and is associated with insulin resistance and PCOS diagnostic criteria.

A mobile phone enabled health promotion program for middle-aged males

The prevalence of chronic diseases among middle aged males outweigh their female counterparts in developed countries. To prevent this, delivery of health promotion programs targeting lifestyle modifications of physical activity and nutrition in middle-aged males has been essential, but often difficult. ManUp health promotion program was a recent initiative that uses current advances in information and communication technology (ICT) to reach the middle-aged males. One of the key components of the ICT approach was the development of smartphone application to enable middle-aged men to uptake the program with their own mobile phone. The smart phone application was aimed at providing varied level of challenges towards physical activity and healthy eating behavior, with interactive and motivational feedback SMS messages. The ManUp program was recently implemented and trialed in a randomized control trial in Gladstone and Rockhampton, Queens. This paper describes the components of the smart phone application integrated within the ManUp health promotion program.

Increased thiamine intake may be required to maintain thiamine status during weight loss in patients with type 2 diabetes

During weight loss, erythrocyte thiamine pyrophosphate (TPP) decreased (221±52 to 195±39 nmol/L, P<0.05) on a diet with adequate thiamine (1.1 mg/day) but was unchanged (217±55 vs 218±52 nmol/L, NS) on a high thiamine diet (2.8 mg/day). Attention to thiamine status may be required in patients with diabetes after weight loss.

The effect of diet and exercise on markers of endothelial function in overweight and obese women with polycystic ovary syndrome

BACKGROUND

Women with polycystic ovary syndrome (PCOS) present with vascular abnormalities, including elevated markers of endothelial dysfunction. There is limited evidence for the effect of lifestyle modification and weight loss on these markers. The aim of this study was to determine if 20 weeks of a high-protein energy-restricted diet with or without exercise in women with PCOS could improve endothelial function.

METHODS

This is a secondary analysis of a subset of 50 overweight/obese women with PCOS (age: 30.3 ± 6.3 years; BMI: 36.5 ± 5.7 kg/m(2)) from a previous study. Participants were randomly assigned by computer generation to one of three 20-week interventions: diet only (DO; n = 14, ≈ 6000 kJ/day), diet and aerobic exercise (DA; n = 16, ≈ 6000 kJ/day and five walking sessions/week) and diet and combined aerobic-resistance exercise (DC; n = 20, ≈ 6000 kJ/day, three walking and two strength sessions/week). At Weeks 0 and 20, weight, markers of endothelial function [vascular cell adhesion molecule-1 (sVCAM-1), inter-cellular adhesion molecule-1 (sICAM-1), plasminogen activator inhibitor-1 (PAI-1) and asymmetric dimethylarginine (ADMA)], insulin resistance and hormonal profile were assessed.

RESULTS

All three treatments resulted in significant weight loss (DO 7.9 ± 1.2%, DA 11.0 ± 1.6%, DC 8.8 ± 1.1; P < 0.001 for time; P = 0.6 time × treatment). sVCAM-1, sICAM-1 and PAI-1 levels decreased with weight loss (P≤ 0.01), with no differences between treatments (P ≥ 0.4). ADMA levels did not change significantly (P = 0.06). Testosterone, sex hormone-binding globulin and the free androgen index (FAI) and insulin resistance also improved (P < 0.001) with no differences between treatments (P ≥ 0.2). Reductions in sVCAM-1 were correlated to reductions in testosterone (r = 0.32, P = 0.03) and FAI (r = 0.33, P = 0.02) as well as weight loss (r= 0.44, P = 0.002). Weight loss was also associated with reductions in sICAM-1 (r= 0.37, P = 0.008).

CONCLUSIONS

Exercise training provided no additional benefit to following a high-protein, hypocaloric diet on markers of endothelial function in overweight/obese women with PCOS.

Self-reported facilitators of, and impediments to maintenance of healthy lifestyle behaviours following a supervised research-based lifestyle intervention programme in patients with type 2 diabetes

INTRODUCTION

Sustainability of healthy lifestyle behaviours following participation in a research-based supervised lifestyle intervention programme is often poor. This study aimed to document factors reported by overweight and obese individuals with Type 2 diabetes as enhancing or impeding sustainability of lifestyle behaviours following participation in such a programme.

METHODS

Thirty patients who completed a 16-week research-based supervised lifestyle intervention programme, incorporating a structured energy restricted diet with or without supervised resistance-exercise training underwent a semi-structured qualitative interview about their experiences in maintaining programme components after 1 year.

RESULTS

Participants maintained 8.8 ± 8.9 kg of the 13.9 ± 6.6 kg weight loss achieved with the research-based supervised lifestyle intervention programme. Only 23% of participants indicated continuation of the complete diet programme. Desire for 'variety' (33%) and increased portion size (27%) were the most commonly reported reasons for discontinuation. Participants who undertook supervised exercise training during the programme indicated access to appropriate programmes/facilities (38%), more affordable gym membership (21%) and having a personal trainer/motivator (17%) would have facilitated exercise continuation.

CONCLUSION

In overweight and obese individuals with Type 2 diabetes, success of the research-based supervised lifestyle intervention programme was perceived as being primarily due to high levels of professional support and supervision, the discontinuation of which subsequently presented difficulties. The interview data provide insight into what people experience following the completion of a research-based intensive lifestyle intervention programme and suggest that programmes assembled for research purposes with the emphasis on compliance may not necessarily promote sustainable change.

The effect of comprehensive lifestyle intervention or metformin on obesity in young women

BACKGROUND AND AIM

Young women are at high risk of weight gain but few weight management interventions have been investigated in this group. This study aimed to determine the effect of metformin on body weight, body composition, metabolic risk factors and reproductive hormone levels in overweight or obese young women compared to placebo and comprehensive lifestyle intervention.

METHODS AND RESULTS

203 overweight or obese young women (BMI 33.2+/-0.3 kg/m², age 28+/-0.3 years) were randomised to 1500 mg/day metformin (M) plus general lifestyle advice, placebo (P) plus general lifestyle advice or comprehensive lifestyle intervention including structured diet, exercise and behavioural therapy (L) for 12-weeks. At 12-weeks, linear mixed models found that L group had greater weight loss (-4.2+/-0.4 kg) compared to M (-1.0+/-0.4 kg) and P groups (-0.2+/-0.3 kg) (P < 0.0001). Weight loss between M and P groups were not significantly different. Attrition rate was 48% for L, 34% for M and 29% for P (P = 0.08). Intention-to-treat analysis showed that 10% (8/79) of the subjects in P group had gained weight (>3%), compared to 3% (2/65) from M group and none (0/59) from L group (P < 0.001). The L group had the greatest decrease in waist circumference (-5.2+/-0.7 cm) and fat mass (-5.4+/-0.7 kg) compared to the other groups (P < 0.05). No significant time-by-group effects were seen in plasma lipids, SHBG, testosterone, blood pressure, serum folate, serum ferritin and serum vitamin B12.

CONCLUSION

Lifestyle intervention was more effective in reducing body weight and improving body composition compared to metformin among healthy overweight or obese young women.

A pilot comprehensive lifestyle intervention program (CLIP)--comparison with qualitative lifestyle advice and simvastatin on cardiovascular risk factors in overweight hypercholesterolaemic individuals

BACKGROUND AND AIMS

Escalating costs of pharmaceuticals for cardiovascular management highlight the need to develop effective lifestyle intervention programs to reduce reliance on these agents. The aim of this pilot study was to evaluate the efficacy of a Comprehensive Lifestyle Intervention Program (CLIP) compared with qualitative lifestyle advice (L) and Simvastatin plus qualitative lifestyle (S+L) on cardiovascular risk factors.

METHODS AND RESULTS

Sixty-five overweight adults with hypercholesterolemia were randomised to either L (qualitative advice on diet, exercise), S+L (20 mg/day Simvastatin plus L) or CLIP (6500 kJ structured menu plan: conventional and functional foods contributing <10% energy from saturated fat, ≥3 g soluble fibre, 2.4 g plant sterols, oily fish ≥2 times/week at lunch and dinner, plus exercise advice and self monitoring) for 6 weeks. LDL-cholesterol was lowered in CLIP (-0.57±0.67 mmol/L, 15%) and S+L (-1.43±0.59 mmol/L, 37%), but did not change significantly in L (-0.17±0.59, 4%) (P<0.001 time-by-treatment interaction). Weight and waist circumference were significantly lowered by CLIP (-4.2±2.2 kg; -5.1±2.3 cm) compared to L (-1.0±1.6 kg; -2.7±3.3 cm) and L+S (-0.7±1.4 kg; -2.4±2.3 cm), (P≤0.003 time-by-treatment interactions). B-carotene levels within treatment groups did not change over time and were not lowered by the CLIP diet compared to L (P>0.05, all). Blood pressure changes were not different between groups.

CONCLUSIONS

The structured CLIP program was more effective than qualitative lifestyle advice in improving weight, waist circumference and LDL-cholesterol without adverse effects on plasma carotenoids over a 6 week period. This program may therefore assist in comprehensive risk factor management, although the sustainability of these benefits needs confirmation.

Timing of protein ingestion relative to resistance exercise training does not influence body composition, energy expenditure, glycaemic control or cardiometabolic risk factors in a hypocaloric, high protein diet in patients with type 2 diabetes

AIM

To investigate timing of protein ingestion relative to resistance exercise training (RT) on body composition, cardiometabolic risk factors, glycaemic control and resting energy expenditure (REE) during weight loss on a high-protein (HP) diet in overweight and obese patients with type 2 diabetes (T2DM).

METHODS

Thirty-four men/women with T2DM (age 57 ± 7 years and body mass index 34.9 ± 4.2 kg m(-2) ) were randomly assigned to the ingestion of a HP meal (860 kJ, 21 g protein, 0.7 g fat, 29.6 g carbohydrate) either immediately prior to RT or at least 2 h following RT. All participants followed a 16-week, energy-restricted (6-7 MJ day(-1) ), HP diet (carbohydrate : protein : fat 43 : 33 : 22) and participated in supervised RT (3 day week(-1) ). Outcomes were assessed pre- and postintervention at 16 weeks.

RESULTS

There was an overall reduction in bodyweight (-11.9 ± 6.1 kg), fat mass (-10.0 ± 4.4 kg), fat-free mass (-1.9 ± 3.1 kg), waist circumference (-12.1 ± 5.3 cm), REE (-742 ± 624 kJ day(-1) ), glucose (-1.9 ± 1.7 mmol l(-1) ), insulin (-6.1 ± 6.7 mU l(-1) ) and glycosylated haemoglobin (-1.1 ± 0.1%), p ≤ 0.01 time for all variables, with no difference between groups (p ≥ 0.41 group effect). Strength improved and cardiometabolic risk factors were reduced similarly in both groups; single repetition maximum chest press 11.0 ± 8.7 kg, single repetition maximum lat pull down 9.9 ± 6.0 kg, total cholesterol -0.6 ± 0.5 mmol l(-1) , high-density lipoprotein cholesterol -0.1 ± 0.2 mmol l(-1) , low-density lipoprotein cholesterol -0.3 ± 0.5 mmol l(-1) , triglycerides -0.6 ± 0.7 mmol l(-1) , blood pressure (systolic/diastolic) -13 ± 10/-7 ± 7 mmHg (p ≤ 0.04 time effect, p ≥ 0.24 group effect).

CONCLUSION

A HP, energy-restricted diet with RT was effective in improving glycaemic control, body composition, strength and cardiometabolic risk factors in overweight/obese patients with T2DM irrespective of altering the timing of protein ingestion relative to RT.

Long-term effects of a low carbohydrate, low fat or high unsaturated fat diet compared to a no-intervention control

BACKGROUND AND AIM

Very low carbohydrate ad libitum diets have been shown to enhance weight loss without increasing cardiometabolic risk factors but no kilojoule-controlled trials have been conducted relative to no intervention. The aim of this study was to compare the changes in weight and other cardiovascular risk factors in 3 isocaloric energy-restricted diets to no-intervention control after 1 year.

METHODS AND RESULTS

One hundred and thirteen subjects (age 47 ± 10 years, BMI 32 ± 6 kg/m(2) with one additional cardiovascular risk factor) were randomly allocated to one of three isocaloric diets (VLC-very low carbohydrate, 60% fat, 4% carbohydrate, n=30; VLF-very low fat, 10% fat, n = 30; HUF-high unsaturated fat, 30% fat, n = 30) with intensive support for 3 months followed by minimal support for 12 months compared to a control group (no intervention, n = 23). The estimated weight change was -3.0 ± 0.2 kg for VLC, -2.0 ± 0.1 kg for VLF, -3.7 ± 0.01 kg for HUF and 0.8 ± 0.5 kg for controls (P=0.065). After correcting for baseline values, decreases in body weight and diastolic blood pressure in the diet groups (-2.9 ± 5.2) were significantly different to the increase in the control group (0.8 ± 5.0) (P<0.05). No differences in cardiovascular risk factors were observed between the diet groups.

CONCLUSION

Significant cardiometabolic risk factor reduction was observed equally with VLC, VLF and HUF diets after 15 months, compared to an exacerbation of risk factors in the control group. At a modest level of adherence, 3 months of intensive support on these dietary patterns confer an improvement in cardiometabolic profile compared to no dietary intervention after 15 months.

Long-term effects of weight loss with a very low carbohydrate and low fat diet on vascular function in overweight and obese patients

OBJECTIVE

To compare the effects of an energy reduced very low carbohydrate, high saturated fat diet (LC) and an isocaloric high carbohydrate, low fat diet (LF) on endothelial function after 12 months.

DESIGN AND SUBJECTS

Forty-nine overweight or obese patients (age 50.0 +/- 1.1 years, BMI 33.7 +/- 0.6 kg m(-2)) were randomized to either an energy restricted ( approximately 6-7 MJ), planned isocaloric LC or LF for 52 weeks. Body weight, endothelium-derived factors, flow-mediated dilatation (FMD), adiponectin, augmentation index (AIx) and pulse wave velocity (PWV) were assessed. All data are mean +/- SEM.

RESULTS

Weight loss was similar in both groups (LC -14.9 +/- 2.1 kg, LF -11.5 +/- 1.5 kg; P = 0.20). There was a significant time x diet effect for FMD (P = 0.045); FMD decreased in LC (5.7 +/- 0.7% to 3.7 +/- 0.5%) but remained unchanged in LF (5.9 +/- 0.5% to 5.5 +/- 0.7%). PWV improved in both groups (LC -1.4 +/- 0.6 m s(-1), LF -1.5 +/- 0.6 m s(-1); P = 0.001 for time) with no diet effect (P = 0.80). AIx and VCAM-1 did not change in either group. Adiponectin, eSelectin, tPA and PAI-1 improved similarly in both groups (P < 0.01 for time).

CONCLUSION

Both LC and LF hypoenergetic diets achieved similar reductions in body weight and were associated with improvements in PWV and a number of endothelium-derived factors. However, the LC diet impaired FMD suggesting chronic consumption of a LC diet may have detrimental effects on endothelial function.

Comparison of aerobic exercise capacity and muscle strength in overweight women with and without polycystic ovary syndrome

OBJECTIVE

To assess maximal aerobic capacity (VO2max) and muscle strength in overweight and obese women with polycystic ovary syndrome (PCOS) and determine their relationship with metabolic and hormonal factors.

DESIGN

Cross-sectional study.

SETTING

Clinical Research Unit.

POPULATION

Overweight and obese women with PCOS (n = 10) and age-and weight-matched healthy controls (n = 16).

METHODS

VO2max was measured during an incremental treadmill test and maximal isometric (ImS) and isokinetic knee extensor strength (IkS) (120 degrees/second) were assessed by isokinetic dynamometry.

MAIN OUTCOME MEASURES

VO2max, ImS, IkS, waist circumference, blood lipids, glucose, insulin, insulin resistance (homeostatic model assessment [HOMA2]), C-reactive protein (CRP), hormonal profile.

RESULTS

PCOS women had higher levels of testosterone and free testosterone (P < or = 0.05), but there were no significant differences in any cardiovascular disease (CVD) risk markers between the groups. VO2max was similar in women with PCOS and healthy controls (PCOS 26.0 +/- 4.1 ml/kg/minute, controls 25.7 +/- 3.8 ml/kg/minute; P = 0.90), as was ImS (PCOS 1.50 +/- 0.54 Nm/kg, controls 1.50 +/- 0.47 Nm/kg; P = 0.96) and IkS (PCOS 1.04 +/- 0.32 Nm/kg, controls 1.16 +/- 0.23 Nm/kg; P = 0.32). VO2max was inversely related to waist circumference, insulin, HOMA2 and CRP. Waist circumference was inversely associated with ImS and IkS. No significant associations between exercise parameters and hormonal variables were identified.

CONCLUSIONS

Compared to age- and weight-matched healthy overweight and obese women with similar insulin resistance and CVD risk profiles, women with PCOS had similar aerobic capacity and muscle strength. This suggests PCOS, at least in the absence of an adverse metabolic profile is unlikely to limit physical function. Larger studies examining the effects of PCOS on exercise tolerance in a diverse range of PCOS phenotypes is required.

Comparison of aerobic exercise capacity and muscle strength in overweight women with and without polycystic ovary syndrome

OBJECTIVE

To assess maximal aerobic capacity (VO2max) and muscle strength in overweight and obese women with polycystic ovary syndrome (PCOS) and determine their relationship with metabolic and hormonal factors.

DESIGN

Cross-sectional study.

SETTING

Clinical Research Unit.

POPULATION

Overweight and obese women with PCOS (n = 10) and age-and weight-matched healthy controls (n = 16).

METHODS

VO2max was measured during an incremental treadmill test and maximal isometric (ImS) and isokinetic knee extensor strength (IkS) (120 degrees/second) were assessed by isokinetic dynamometry.

MAIN OUTCOME MEASURES

VO2max, ImS, IkS, waist circumference, blood lipids, glucose, insulin, insulin resistance (homeostatic model assessment [HOMA2]), C-reactive protein (CRP), hormonal profile.

RESULTS

PCOS women had higher levels of testosterone and free testosterone (P < or = 0.05), but there were no significant differences in any cardiovascular disease (CVD) risk markers between the groups. VO2max was similar in women with PCOS and healthy controls (PCOS 26.0 +/- 4.1 ml/kg/minute, controls 25.7 +/- 3.8 ml/kg/minute; P = 0.90), as was ImS (PCOS 1.50 +/- 0.54 Nm/kg, controls 1.50 +/- 0.47 Nm/kg; P = 0.96) and IkS (PCOS 1.04 +/- 0.32 Nm/kg, controls 1.16 +/- 0.23 Nm/kg; P = 0.32). VO2max was inversely related to waist circumference, insulin, HOMA2 and CRP. Waist circumference was inversely associated with ImS and IkS. No significant associations between exercise parameters and hormonal variables were identified.

CONCLUSIONS

Compared to age- and weight-matched healthy overweight and obese women with similar insulin resistance and CVD risk profiles, women with PCOS had similar aerobic capacity and muscle strength. This suggests PCOS, at least in the absence of an adverse metabolic profile is unlikely to limit physical function. Larger studies examining the effects of PCOS on exercise tolerance in a diverse range of PCOS phenotypes is required.

The effect of weight loss on anti-Müllerian hormone levels in overweight and obese women with polycystic ovary syndrome and reproductive impairment

BACKGROUND

Anti-Müllerian hormone (AMH) has been proposed as a clinical predictor of improvements in reproductive function following weight loss in overweight and obese women with polycystic ovary syndrome (PCOS). This study aimed to assess whether baseline and/or change in AMH levels with weight loss predict improvements in reproductive function in overweight and obese women with PCOS.

METHODS

Fifty-two overweight and obese women with PCOS and reproductive impairment (age 29.8 +/- 0.8 years, BMI 36.5 +/- 0.7 kg/m(2)) followed a 20-week weight loss programme. AMH, weight, menstrual cyclicity and ovulatory function were assessed at baseline and post-intervention.

RESULTS

Participants who responded with improvements in reproductive function (n = 26) had lower baseline AMH levels (23.5 +/- 3.7 versus 32.5 +/- 2.9 pmol/l; P = 0.03) and experienced greater weight loss (-11.7 +/- 1.2 versus -6.4 +/- 0.9 kg; P = 0.001) compared with those who did not respond (n = 26). Logistic regression analysis showed that weight loss and baseline AMH were independently related to improvements in reproductive function (P = 0.002 and P = 0.013, respectively). AMH levels did not change with weight loss in both responders and non-responders.

CONCLUSIONS

In overweight and obese women with PCOS and reproductive dysfunction, a 20-week weight loss intervention resulted in improvements in reproductive function but no change in AMH levels.

CLINICAL TRIALS REGISTRATION NUMBER

ACTRN12606000198527.

Effect of caloric restriction with and without exercise training on oxidative stress and endothelial function in obese subjects with type 2 diabetes

AIM

Effects of dietary weight loss on endothelial function, particularly when combined with exercise training, is largely unknown in type 2 diabetes. We sought to determine whether aerobic exercise training provided any additional improvements in endothelial function, oxidative stress or other established markers of cardiovascular risk when combined with an energy-restricted diet in patients with type 2 diabetes.

METHODS

In a parallel study design, 29 sedentary, overweight and obese patients with type 2 diabetes (age 52.4 +/- 1.4 years and BMI 34.2 +/- 0.9 kg/m(2)) were randomized to a 12-week moderate energy-restricted diet (~5000 kJ/day and approximately 30% energy deficit) with or without aerobic exercise training [diet only (D), n = 16 and diet plus exercise (DE), n = 13]. Body weight, cardiovascular risk markers, malondialdehyde (MDA, oxidative stress marker), 24-h urinary nitrate/nitrite and flow-mediated dilatation (FMD) of the brachial artery were measured pre- and postintervention.

RESULTS

Both interventions reduced body weight (D 8.9%, DE 8.5%, time effect p < 0.001). Significant reductions in body fat, waist circumference, blood pressure, glycated haemoglobin, glucose, insulin resistance, lipids and MDA and increases in urinary nitrite/nitrate were observed in both groups (time effect p < or = 0.05); however, these changes were not different between treatments. At baseline, FMD was similar in both groups (D 2.5 +/- 0.9%, DE 4.2 +/- 1.2%; p = 0.25) and did not change after the interventions (p = 0.59).

CONCLUSIONS

These results suggest that lifestyle interventions incorporating diet with or without exercise improve glycaemic control, reduce oxidative stress and improve other cardiovascular risk factors but do not improve FMD in obese subjects with type 2 diabetes.

Subependymal nodules, giant cell astrocytomas and the tuberous sclerosis complex: a population-based study

OBJECTIVES

(1) In a population-based study of tuberous sclerosis (TSC), to identify the number of patients presenting with symptomatic giant cell astrocytomas (GCAs); (2) within a subset of this population, to identify the number who would be diagnosed with GCAs on predetermined radiological criteria.

METHODS

Patients with TSC in Wessex (a geographical region of England) were identified, and their medical history determined. A subset were invited to have a cranial MRI if they did not have a history of a symptomatic GCA and if they were likely to tolerate cranial imaging without a general anaesthetic. Scans were performed according to a standard protocol on a single scanner and were reported blindly by a neuroradiologist.

RESULTS

179 people were identified with TSC. Ten of these had a history of treatment for a symptomatic GCA. Forty-one of the remainder had a cranial MRI. Thirty-nine of these had subependymal nodules, of whom 24 (59%) had at least one (maximum 11) that showed enhancement with gadolinium. In seven (17%), the lesion was >1 cm, and all of these lesions showed gadolinium enhancement.

CONCLUSIONS

In this study, the proportion of patients with TSC who had a history of symptomatic GCA was 5.6%. In the subset without such a history, who underwent imaging, the number diagnosed as having a GCA on radiological criteria was much higher (59% gadolinium enhancement and 17% >1 cm in size). Screening for GCAs (performing scans on asymptomatic patients with TSC) would therefore identify large numbers of patients who had not presented with symptoms. This finding leads us to recommend that screening should not be undertaken.

Appetite hormones and energy intake in obese men after consumption of fructose, glucose and whey protein beverages

OBJECTIVE

To investigate appetite responses over 4 h to fructose beverages in obese men, relative to glucose and whey protein. Second, to investigate the effect of combining whey and fructose on postprandial appetite hormones.

DESIGN

Randomized, double-blind crossover study of four beverages (1.1 MJ) containing 50 g of whey, fructose, glucose or 25 g whey+25 g fructose. Blood samples and appetite ratings were collected for 4 h then a buffet meal was offered.

SUBJECTS

Twenty-eight obese men (age: 57.0+/-1.6 years, body mass index: 32.5+/-0.6 kg/m(2)).

MEASUREMENTS

Plasma ghrelin (total), glucagon-like peptide-1 (GLP-1 7-36), cholecystokinin-8, glucose, insulin and appetite ratings were assessed at baseline and 30, 45, 60, 90, 120, 180, 240 min after beverages, followed by measurement of ad libitum energy intake.

RESULTS

Fructose produced lower glycaemia and insulinaemia compared to the glucose treatment (P<0.0001); whereas postprandial ghrelin, GLP-1 and cholecystokinin responses were similar after both treatments. Whey protein produced a prolonged (2-4 h) suppression of ghrelin (P=0.001) and elevation of GLP-1 (P=0.002) and cholecystokinin (P=0.003) that were reduced when combined with fructose, while glucose and insulin responses were similar. Energy intake after 4 h was independent of beverage type (glucose 4.7+/-0.2 MJ; fructose 4.9+/-0.3 MJ; whey 4.6+/-0.3 MJ; whey/fructose 4.8+/-0.3 MJ; P>0.05).

CONCLUSION

In obese men, fructose- and glucose-based beverages had similar effects on appetite and associated regulatory hormones, independent of the differing glycaemic and insulinaemic responses. The contrasting profile of plasma ghrelin, GLP-1 and cholecystokinin after whey protein consumption did not impact on ad libitum intake 4 h later and was attenuated when 50% of whey was replaced with fructose.

CT colonography: interpretative performance in a non-academic environment

AIM

To investigate interpretative accuracy and reporting time for radiologists performing computed tomography (CT) colonography in day-to-day non-academic clinical practice.

MATERIALS AND METHODS

Thirteen radiologists from seven centres, who were reporting CT colonography in non-academic daily clinical practice, interpreted a dataset of 15 colonoscopically validated cases in a controlled environment. Ten cases had either a cancer or polyp >10mm; one case had a medium polyp and four were normal. Correct case categorization and interpretation times were compared using analysis of variance to aggregated results obtained from both experienced observers and observers recently trained using 50 cases, working in an academic environment. The effect of experience was determined using Spearman's rank correlation.

RESULTS

Individual accuracy was highly variable, range 53% (95% CI 27-79%) to 93% (95% CI 68-100%). Mean accuracy overall was significantly inferior to experienced radiologists (mean 75 versus 88%, p=0.04) but not significantly different from recently trained radiologists (p=0.48). Interpretation time was not significantly different to experienced readers (mean 12.4 min versus 11.7, p=0.74), but shorter than recently trained radiologists (p=0.05). There was a significant, positive, linear correlation between prior experience and accuracy (p<0.001) with no plateau.

CONCLUSION

Accuracy for sub-specialist radiologists working in a non-academic environment is, on average, equivalent to radiologists trained using 50 cases. However, there is wide variability in individual performance, which generally falls short of the average performance suggested by meta-analysis of published data. Experience improves accuracy, but alone is insufficient to determine competence.

Effects of meals with high soluble fibre, high amylose barley variant on glucose, insulin, satiety and thermic effect of food in healthy lean women

OBJECTIVE

To examine the effect of barley flour (barley cultivar, Hordeum Vulgare var Himalaya 292) incorporated into breakfast and lunch compared with otherwise identical meals containing white wheat flour on the thermic effect of food (TEF), subsequent food intake and metabolic parameters.

DESIGN

Randomized single blinded crossover study.

SETTING

Outpatient setting.

SUBJECTS AND METHODS

Fourteen healthy women consumed a test breakfast at 0700 h. Energy expenditure, respiratory quotient (RQ), appetite ratings using a visual analogue scale (VAS), insulin and glucose levels were measured before and after a test lunch at 1330 h. Food intake was recorded for the remainder of the day.

RESULTS

The TEF was 5% for both test lunches and meal type did not affect any variable measured by the VAS. There was an increase in post-prandial RQ above baseline (0.80) independent of treatment (0.88 and 0.90 for barley and wheat-containing meals, respectively, P<0.001). Mean area under the glycaemic response curve (AUC) for wheat-containing meals was 4.68+/-1.67 mmol/l/h, 22% higher than for the barley-containing meals (3.67+/-1.91 mmol/l/h), P=0.05. AUC of insulin in response to wheat-containing meals (78.1+/-35.3 mIU/l/h) was 32% greater than barley-containing meals (52.8+/-24.7 mU/l/h), P<0.02. Ad libitum food intake over the next 10 h was reduced by 23% (9.6 vs 11.0 MJ, P<0.05) after the wheat-containing meals compared to the barley-containing glycaemic index meals.

CONCLUSION

Inclusion of an ingredient containing increased soluble fibre and amylose did not reduce spontaneous food intake but rather was associated with higher subsequent energy intakes despite its reduced glycaemic and insulinemic effects.

SPONSORSHIP

CSIRO, Human Nutrition, Adelaide, Australia.

Flow-mediated dilatation in overweight and obese women with polycystic ovary syndrome

OBJECTIVE

There remains a large degree of disagreement about the association of polycystic ovary syndrome (PCOS) with impaired endothelial dysfunction and cardiovascular disease (CVD) risk. The purpose of this study was to determine whether overweight and obese women with PCOS have impaired endothelial function compared with weight-matched controls without PCOS and whether endothelial function is associated with cardiovascular risk markers and hormonal parameters.

DESIGN

Cross-sectional analysis.

SETTING

An outpatient trial at the Commonwealth Scientific Industrial Research Organisation Clinical Research Unit.

POPULATION

Overweight and obese women with PCOS (n= 12) and weight-matched controls without PCOS (n= 10).

METHODS

Endothelial function, cardiovascular risk markers and hormonal parameters were assessed in the patients.

MAIN OUTCOME MEASURES

Endothelial function was assessed by flow-mediated dilatation (FMD) of the brachial artery using high-resolution ultrasound. Lipid profile, fasting insulin level, glucose level, insulin resistance, C-reactive protein level, folate level, Vitamin B(12) level and hormonal parameters.

RESULTS

Women with PCOS had significantly higher testosterone levels (P < 0.001) and free androgen index (P= 0.006) compared with the controls without PCOS. Both groups were normoinsulinaemic, and there were no significant differences in any of the markers of CVD between women with and without PCOS. Furthermore, FMD was similar in both groups (PCOS 6.1 +/- 1.2% versus control 5.6 +/- 1.0%, P= 0.77).

CONCLUSIONS

Compared with a group of weight-matched women with similar metabolic profiles, normoinsulinemic, overweight and obese women with PCOS did not show any greater impairment in endothelial function assessed by FMD. A normoinsulinemic phenotype of PCOS with low metabolic risk factors may reduce the risk of endothelial dysfunction in overweight and obese women with this syndrome. Further studies are required that directly compare FMD in normoinsulinemic and hyperinsulinaemic women with PCOS.

Lifestyle choices, diet, and insulin sensitizers in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is significantly affected by environmental regulators impacting on genetic predisposition. Lifestyle changes can significantly modulate the phenotype of this disease. Diet, exercise, smoking, stress, and other factors adversely affect reproductive outcomes in PCOS. These influences can be modulated by structure change in an individual or group. Lifestyle choices should be discussed in this group of patients. The role of insulin sensitizers, including metformin, has still to be determined in this condition.

Effect of calcium and dairy foods in high protein, energy-restricted diets on weight loss and metabolic parameters in overweight adults

OBJECTIVE

To compare the effects two high-protein (HP) diets that differ in dietary calcium and protein source on weight loss, body composition, glucose and lipid metabolism, markers of liver function, fibrinolysis and endothelial function and blood pressure.

DESIGN

Randomized, parallel study (12 wk of energy restriction, 4 wk of energy balance) of high dairy protein/high-calcium (DP, 2400 mg Ca/d) and high mixed protein/moderate calcium (MP, 500 mg Ca/d) diets (5.5 MJ/d, 34% protein, 41% carbohydrate, 24% fat).

SUBJECTS

In all, 50 healthy, overweight (age 25-64 y; body mass index 25-35 kg/m(2);) males (n=20) and females (n=30).

RESULTS

Loss of total weight (-9.7+/-3.8 kg), fat mass (-8.3+/-0.4 kg) and lean mass (-1.6+/-0.3 kg) were independent of dietary group. Improvements in fasting insulin, lipids, systolic/diastolic blood pressure, and markers of liver function, fibrinolysis and endothelial function were independent of dietary intervention.

CONCLUSIONS

Increased dietary calcium/dairy foods in an energy-restricted, HP diet does not affect weight loss or body composition. Weight reduction following increased protein diets is associated with beneficial metabolic outcomes that are not affected by protein source.

Effect of weight loss on inflammatory and endothelial markers and FMD using two low-fat diets

OBJECTIVE

Cardiovascular disease is strongly associated with obesity and there is evidence that weight loss has positive effects on cardiovascular disease risk. The aims of this study were to compare meal replacements (MR) with a conventional low-fat diet as weight loss strategies and to examine the effect of weight loss on flow-mediated dilatation (FMD) and other markers of endothelial function in overweight Australians with raised triglycerides (TG) (> 2 mmol/l).

RESEARCH METHODS

Subjects matched for age, gender, fasting plasma TG and body mass index were randomized to two low- fat high- carbohydrate weight loss strategies (both < 6000 kJ), one using MR and the other a structured eating plan, control (C). Subjects followed both diets for 3 months. In total, 55 subjects completed the study. FMD, pulse wave velocity and blood pressure (BP) were measured at baseline and at 3 months, as were fasting blood samples for lipids, glucose, insulin, C reactive protein (CRP) and endothelium-derived factors.

RESULTS

Mean weight loss was 6.3 +/- 3.7 kg (6.0 +/- 4.2 vs 6.63 +/- 3.35 kg, MR vs C) with no difference between diet groups. TG, insulin, CRP, plasminogen activator inhibitor 1 (PAI-1) and soluble intracellular adhesion molecule-1 (sICAM1) fell after weight loss, but FMD did not change. Systolic BP fell by 8 mmHg and pulse wave velocity improved.

DISCUSSION

In subjects with elevated TG, weight loss resulted in significant improvements in cardiovascular risk markers, particularly endothelium-derived factors (PAI-1 and sICAM1). However, FMD did not improve with weight loss.

Population and virulence factor dynamics in fecalEscherichia colifrom healthy adults consuming weight control diets

Individual susceptibility to gastrointestinal infection is seen commonly in food poisoning outbreaks, but factors (such as diet) which may modulate this variability are understood poorly. Similarly, factors altering the population dynamics of enteric non-pathogenic Escherichia coli or of pathogenic E. coli containing toxin-signature DNA sequences in the colonic flora of healthy individuals are largely unknown. Feces were collected 4 times over a 12 week period from 41 healthy volunteer adults on a weight control diet (high or low in fiber). E. coli strains were examined by conventional culture followed by PCR for virulence genes stx1, stx2, eae and hlyA, and polymorphic β-glucuronidase. Total E. coli counts ranged from undetectable to 8.75 log10CFU/g feces and were unaffected by dietary fiber consumption or gender. Total E. coli counts were correlated positively with age (r = 0.401, P < 0.05). Fifty-eight percent (n = 24) of study individuals harboured more than 1 morph of β-glucuronidase, indicating the presence of more than 1 strain of E. coli. Virulence genes were detected in 12 of 41 adults, comprising 10 stx1, 3 stx2, 3 eae, and 0 hlyA, but occurrence was not associated with diet, gender, or age. Factors influencing strain mobility over time did not appear to include diet or gender, while the positive relationship between total E. coli numbers and increasing age suggests that some older individuals are "more permissive" to mobile E. coli, including those with toxin genes.Key words: Escherichia coli, virulence, healthy humans, diet.

Long-term effects of advice to consume a high-protein, low-fat diet, rather than a conventional weight-loss diet, in obese adults with type 2 diabetes: one-year follow-up of a randomised trial

AIMS/HYPOTHESIS

This study compared the long-term weight loss and health outcomes at 1-year follow-up, after a 12-week intensive intervention consisting of two low-fat, weight-loss diets, which differed in protein content.

METHODS

We randomly assigned 66 obese patients (BMI: 27-40 kg/m2) with type 2 diabetes to either a low-protein (15% protein, 55% carbohydrate) or high-protein diet (30% protein, 40% carbohydrate) for 8 weeks of energy restriction (approximately 6.7 MJ/day) and 4 weeks of energy balance. Subjects were asked to maintain the same dietary pattern for a further 12 months of follow-up.

RESULTS

The study was completed by 38 of the subjects, with equal dropouts in each group. At Week 64, weight reductions against baseline were -2.2+/-1.1 kg (low protein) and -3.7+/-1.0 kg (high protein), p<0.01, with no diet effect. Fat mass was not different from baseline in either group. At Week 12, both diets reduced systolic and diastolic blood pressure by 6 and 3 mm Hg respectively, but blood pressure increased more with weight regain during follow-up in the low-protein group (p< or =0.04). At Week 64, both diets significantly increased HDL cholesterol and lowered C-reactive protein concentrations. There was no difference in the urinary urea : creatinine ratio at baseline between the two groups, but this ratio increased at Week 12 (in the high-protein group only, p<0.001, diet effect), remaining stable during follow-up in both diets.

CONCLUSIONS/INTERPRETATION

A high-protein weight-reduction diet may in the long term have a more favourable cardiovascular risk profile than a low-protein diet with similar weight reduction in people with type 2 diabetes.

Ghrelin and measures of satiety are altered in polycystic ovary syndrome but not differentially affected by diet composition

Polycystic ovary syndrome (PCOS) is a common endocrine condition in women of reproductive age associated with obesity. It may involve dysregulation of ghrelin, a hormone implicated in appetite regulation. The effect of diet composition on ghrelin is unclear. Overweight women with and without PCOS were randomized to a high-protein (40% carbohydrate, 30% protein; 10 PCOS, six non-PCOS) or standard protein diet (55% carbohydrate, 15% protein; 10 PCOS, six non-PCOS) for 12 wk of energy restriction and 4 wk of weight maintenance. Diet composition had no effect on fasting or postprandial ghrelin or measures of satiety. Non-PCOS subjects had a 70% higher fasting baseline ghrelin (P = 0.011), greater increase in fasting ghrelin (57.5 vs. 34.0%, P = 0.033), and greater maximal decrease in postprandial ghrelin after weight loss (-144.1 +/- 58.4 vs. -28.9 +/- 14.2 pg/ml, P = 0.02) than subjects with PCOS. Subjects with PCOS were less satiated (P = 0.001) and more hungry (P = 0.007) after a test meal at wk 0 and 16 than subjects without PCOS. Appetite regulation, as measured by subjective short-term hunger and satiety and ghrelin homeostasis, may be impaired in PCOS.

Cholesterol-lowering effects of plant sterol esters differ in milk, yoghurt, bread and cereal

OBJECTIVE

To measure the relative effects of each of four phytosterol ester-enriched low-fat foods (bread, breakfast cereal, milk and yoghurt) on serum lipids, plasma phytosterols and carotenoids.

DESIGN

: Three research centres undertook a randomised, incomplete crossover, single-blind study consisting of four treatment periods of 3 weeks each, one of which was a control period. Each sterol-enriched test food provided 1.6 g/day of phytosterols as sterol esters.

SETTING

General Community.

SUBJECTS

In all 58, free-living men and women with mean age (s.d.) 54 (8) y, moderately elevated plasma total cholesterol 6.2 (0.7) mmol/l and body mass index 26.2 (3.0) kg/m(2).

MAIN OUTCOME MEASURES

Serum lipids, plasma phytosterols and carotenoids.

RESULTS

Serum total and LDL cholesterol levels were significantly lowered by consumption of phytosterol-enriched foods: milk (8.7 and 15.9%) and yoghurt (5.6 and 8.6%). Serum LDL cholesterol levels fell significantly by 6.5% with bread and 5.4% with cereal. They were both significantly less efficacious than sterol-enriched milk (P<0.001). Plasma sitosterol increased by 17-23% and campesterol by 48-52% with phytosterol-enriched milk and bread. Lipid-adjusted beta-carotene was lowered by 5-10% by sterols in bread and milk, respectively.

CONCLUSIONS

This is the first study to demonstrate that cholesterol-lowering effects of plant sterol esters may differ according to the food matrix. Plant sterols in low-fat milk was almost three times more effective than in bread and cereal. Despite phytosterol-enriched cereal products resulting in lower serum cholesterol reductions compared to sterol-enriched milk, the detection of similar changes in plasma phytosterols demonstrated that such products still delivered and released phytosterols to the gut.

The relation of infantile spasms, tubers, and intelligence in tuberous sclerosis complex

BACKGROUND

The aetiology of the learning difficulty in tuberous sclerosis is debated. It may be related to the amount of tubers in the brain or caused by the infantile spasms that occur in early life.

AIMS

To examine the relative contributions to final intelligence (IQ) made by both cerebral tubers and infantile spasms.

METHODS

As part of an epidemiological study of tuberous sclerosis in the south of England, patients were recruited who were able to undergo magnetic resonance imaging (MRI) without the need for an anaesthetic. Epilepsy history was determined by interview and review of clinical records. IQ was assessed using either Wechsler intelligence scales or Raven's matrices.

RESULTS

A total of 41 patients consented to have an MRI scan. IQ scores were normally distributed about a mean of 91. Twenty six patients had a positive history of epilepsy, and 11 had suffered from infantile spasms. There was a significant relation between the number of tubers and IQ. Infantile spasm status partly confounded the relation between tubers and IQ, but did not render the relation statistically insignificant. The relation between infantile spasms and learning difficulty remained strong even when controlling for the number of tubers.