Is a failure to recognize an increase in food intake a key to understanding insulin-induced weight gain?

Providing lifestyle advice to women with PCOS: an overview of practical issues affecting success

Polycystic Ovary Syndrome (PCOS) is a common endocrine disorder affecting up to 13 % of women. Lifestyle interventions are first-line treatments, however attrition in women with PCOS is high. This review summarises current evidence on barriers to lifestyle management in PCOS and suggested strategies for overcoming these challenges, mapped to the Capability, Opportunity, Motivation and Behaviour model.Physical capability for lifestyle changes may be impacted by altered gut hormone regulation and energy expenditure in PCOS. This may contribute to difficulties with weight management. The higher prevalence of eating disorders, disordered eating, fatigue and sleep disturbances are further barriers. Psychological capability may be reduced due psychological symptoms and lack of critical health literacy. Women with PCOS face similar challenges in terms of Opportunity to make lifestyle changes as other women of reproductive age. However, these are complicated by features more common in PCOS including body dissatisfaction. Motivation to adopt healthy lifestyles may be impacted by suboptimal risk perception and intrinsic motivation.To address these barriers, screening for and management of eating disorders, disordered eating, depression, and Obstructive Sleep Apnoea should be undertaken as per international evidence-based guidelines. A weight-neutral approach may be appropriate with disordered eating. Building capability among health professionals to better partner with women with PCOS on their management is essential in addressing health literacy gaps. Behavioural strategies that target risk perception and build intrinsic motivation should be utilised. More research is required to understand optimal self-management strategies, risk perception, energy homeostasis and overcoming attrition in women with PCOS.

Weight gain and lifestyle factors in women with and without polycystic ovary syndrome

STUDY QUESTION

Do extrinsic factors including lifestyle, psychosocial factors and healthcare professional engagement independently contribute to weight gain in women with and without polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

Women with PCOS had a higher rate of weight gain than women without PCOS which was most marked in those with unhealthy lifestyles.

WHAT IS KNOWN ALREADY

Women with PCOS have a higher prevalence of overweight/obesity and greater weight gain than women without PCOS. The association of lifestyle factors with weight change in PCOS is not known.

STUDY DESIGN, SIZE, DURATION

The study was a population-based observational study with data collected from seven surveys over 19 years (N = 14 127; Survey 1) involving women with and without PCOS.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We used data from the 1973-1978 birth cohort of the Australian Longitudinal Study on Women's Health.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with PCOS gained more weight annually (0.26 kg/year; 95% CI 0.12, 0.39; P < 0.0001) and over 19 years (4.62 kg; 95% CI 3.04, 6.21; P < 0.0001) than women without PCOS (adjusted analyses). For all women, there were positive associations between weight gain and energy intake, sitting time and stress; inverse associations with fibre intake and physical activity (PA); and no associations with diet quality, glycaemic index, healthcare utilization, depression or anxiety. There were interactions between lifestyle factors (energy intake P = 0.006, glycaemic index P = 0.025, sitting time P = 0.041 and PA P = 0.021), PCOS status and time such that weight gain varied between women with and without PCOS according to these factors.

LIMITATIONS, REASONS FOR CAUTION

The limitations of this study include the use of self-reported measures such as diet, PA, sitting time, psychological factors and health care utilization.

WIDER IMPLICATIONS OF THE FINDINGS

While women with PCOS are more prone to weight gain, lifestyle factors have a more profound impact on weight gain in women with PCOS than without PCOS. These study findings have implications for understanding the mechanisms of weight gain in women with PCOS. They also highlight the importance of early lifestyle intervention as soon as PCOS is diagnosed to address modifiable extrinsic factors and prevent excess weight gain and worsening of the clinical features of PCOS.

STUDY FUNDING/COMPETING INTEREST(S)

M.A.A. is funded by the Monash International Tuition Scholarship and Monash Graduate Scholarship and L.J.M. is funded by a National Heart Foundation Future Leader Fellowship. The authors declared no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Cytotoxicity Analysis of Morphologically Different Sol-Gel-Synthesized MgO Nanoparticles and Their In Vitro Insulin Resistance Reversal Ability in Adipose cells

Insulin resistance is one of the major factors that leads to type 2 diabetes. Although insulin therapies have been shown to overcome insulin resistance, overweight and hypoglycemia are still observed in most cases. The disadvantages of insulin therapies have driven the interest in developing novel curative agents with enhanced insulin resistance reversibility. Magnesium deficiency has also been recognized as a common problem which leads to insulin resistance in both type 1 and 2 diabetes. Oxide nanoparticles demonstrate highly tunable physicochemical properties that can be exploited by engineers to develop unique oxide nanoparticles for tailored applications. Magnesium supplements for diabetic cells have been reported to increase the insulin resistance reversibility. Hence, it is hypothesized that magnesium oxide (MgO) nanoparticles could be molecularly engineered to offer enhanced therapeutic efficacy in reversing insulin resistance. In the present work, morphologically different MgO nanoparticles were synthesized and evaluated for biophysical characteristics, biocompatibility, cytotoxicity, and insulin resistance reversibility. MTT assay revealed that hexagonally shaped MgO nanoparticles are less toxic to 3T3-L1 adipose cells (diabetic) compared with spherically and rod-shaped MgO nanoparticles. MTT assays using VERO cells (normal, non-diabetic) showed that 400 μg/ml of hexagonal MgO nanoparticles were less toxic to both diabetic and non-diabetic cells. DNS glucose assay and western blot showed that hexagonally shaped MgO nanoparticles had reversed 29.5% of insulin resistance whilst fluorescence microscopy studies indicated that the insulin resistance reversal is due to the activation of intracellular enzymes. The probable mechanism for MgO nanoparticles to induce cytotoxic effect and insulin resistance reversal is discussed.

Sucralose Promotes Food Intake through NPY and a Neuronal Fasting Response

Non-nutritive sweeteners like sucralose are consumed by billions of people. While animal and human studies have demonstrated a link between synthetic sweetener consumption and metabolic dysregulation, the mechanisms responsible remain unknown. Here we use a diet supplemented with sucralose to investigate the long-term effects of sweet/energy imbalance. In flies, chronic sweet/energy imbalance promoted hyperactivity, insomnia, glucose intolerance, enhanced sweet taste perception, and a sustained increase in food and calories consumed, effects that are reversed upon sucralose removal. Mechanistically, this response was mapped to the ancient insulin, catecholamine, and NPF/NPY systems and the energy sensor AMPK, which together comprise a novel neuronal starvation response pathway. Interestingly, chronic sweet/energy imbalance promoted increased food intake in mammals as well, and this also occurs through an NPY-dependent mechanism. Together, our data show that chronic consumption of a sweet/energy imbalanced diet triggers a conserved neuronal fasting response and increases the motivation to eat.

Diabetes-related distress, insulin dose, and age contribute to insulin-associated weight gain in patients with type 2 diabetes: results of a prospective study

OBJECTIVE

The determinants of insulin-associated weight gain in type 2 diabetes mellitus (T2DM) are partly unknown. Therefore, we conducted a prospective study to identify predictors of insulin-associated weight gain.

RESEARCH DESIGN AND METHODS

In patients with T2DM, we assessed physical activity by accelerometry and measured diabetes-related distress by questionnaires before and 6 and 12 months after starting insulin therapy. Glycemic control (HbA1c) and insulin dose were monitored.

RESULTS

After 12 months of insulin therapy, mean body weight had increased by 3.0 ± 2.5 kg (P < 0.001). The drop in HbA1c was correlated with insulin-associated weight gain. With the use of a multiple linear regression model, a cluster of variables was identified that significantly related to weight gain. Diabetes-related distress, initial insulin dose, and the increase of insulin dose during the course of the study as well as age appeared to be important predictors of weight gain after initiation of insulin therapy. Physical activity (measured as MET) decreased from 1.40 ± 0.04 at baseline to 1.32 ± 0.04 MET (P < 0.05) but was not significantly related to weight changes.

CONCLUSIONS

Diabetes-related distress, initial and titration of insulin dose, and age all significantly predict insulin-associated weight gain. After the initiation of insulin therapy, physical activity decreased significantly, but this did not determine weight gain over the first 12 months. Our study findings may have clinical implications.

Changes in weight and BMI following the diagnosis of type 1 diabetes in children and adolescents

The aim of this study was to study weight and body mass index (BMI) before, at, and after diagnosis of type 1 diabetes (T1D) and to identify factors associated with weight gain. Studied retrospectively were 209 children <18 years with T1D followed for 6 years. Data collected included clinical and laboratory data before diagnosis, at diagnosis, and during 6 years of follow-up. Anthropometric parameters of patients were compared along follow-up and with those of their parents and siblings. Mean BMI-standard deviation score (SDS) was below average at diagnosis (-0.66 ± 1.27), had increased to 0.37 ± 0.93 at 3 months, and decreased to a nadir at 6 months in females and 12 months in males; between 1 and 3 years, there was a slight increase and between 3 and 6 years a further increase only in the females. BMI-SDS at 6 years was significantly higher than pre-diabetes BMI-SDS (0.35 ± 0.83 vs. -0.04 ± 1.23, p < 0.001). Patients' BMI-SDS at 6 years was similar to that of their parents and siblings, was higher in the females (0.53 ± 0.74 vs. 0.27 ± 0.82, p = 0.02) and in those keeping diabetes a secret (0.66 ± 0.82 vs. 0.33 ± 0.78, p = 0.027), and was not associated with age or pubertal stage at diagnosis, ethnicity, or metabolic control. A longer duration of insulin pump therapy was associated with a lower BMI-SDS (r = -0.2375, p < 0.025). BMI-SDS increased during the 6 years following diagnosis of T1D in pediatric patients, especially in the females, but remained in the normal range and was similar to that of other family members.

The central insulin system and energy balance

Insulin acts throughout the body to reduce circulating energy and to increase energy storage. Within the brain, insulin produces a net catabolic effect by reducing food intake and increasing energy expenditure; this is evidenced by the hypophagia and increased brown adipose tissue sympathetic nerve activity induced by central insulin infusion. Reducing the activity of the brain insulin system via administration of insulin antibodies, receptor antisense treatment, or receptor knockdown results in hyperphagia and increased adiposity. However, despite decades of research into the role of central insulin in food intake, many questions remain to be answered, including the underlying mechanism of action.

Insulin detemir reduces weight gain as a result of reduced food intake in patients with type 1 diabetes

OBJECTIVE

Insulin detemir lacks the usual propensity for insulin to cause weight gain. We investigated whether this effect was a result of reduced energy intake and/or increased energy expenditure.

RESEARCH DESIGN AND METHODS

A 32-week, randomized crossover design trial was undertaken in 23 patients with type 1 diabetes. Patients on a basal-bolus regimen (with insulin aspart as the bolus insulin) were randomly assigned to insulin detemir or NPH insulin as a basal insulin for 16 weeks, followed by the other basal insulin for 16 weeks. At the end of each 16-week period, total energy expenditure, resting energy expenditure, diet-induced thermogenesis, activity energy expenditure, energy intake, weight change, glycemic control, hypoglycemic episodes, and hormones that affect satiety and fuel partitioning were measured.

RESULTS

After 16 weeks, weight change was -0.69±1.85 kg with insulin detemir and +1.7±2.46 kg with NPH insulin (P<0.001). Total energy intake was significantly less with insulin detemir (2,016±501 kcal/day) than with NPH insulin (2,181±559 kcal/day) (P=0.026). There was no significant difference in any measure of energy expenditure, HbA1c percentage, or number of hypoglycemic episodes. Leptin was lower and resistin was higher with insulin detemir compared with NPH insulin (P=0.039, P=0.047). After the meal, ghrelin and pancreatic polypeptide levels (P=0.002, P=0.001) were higher with insulin detemir.

CONCLUSIONS

The reduced weight gain with insulin detemir compared with NPH insulin is attributed to reduced energy intake rather than increased energy expenditure. This may be mediated by a direct or indirect effect of insulin detemir on the hormones that control satiety.

Long-term impact of a structured group-based inpatient-education program for intensive insulin therapy in patients with diabetes mellitus

PURPOSE

Structured patient education aiming to improve self-management strategies might be beneficial for insulin-treated diabetic patients. However, in previous studies the extent of the benefit has been inconsistent in different subgroups of patients. The aim of the present study was to assess the potential benefit of a structured inpatient-education program for intensive insulin therapy according to the basal-bolus concept with particular emphasis on self-management strategies.

METHODS

We included 81 diabetic patients (59 with type 1, 14 with type 2, eight with other forms) in this retrospective longitudinal study; all had completed the training program on eight consecutive days at a university clinic between 2003 and 2005. Data assessment included HbA1c, LDL-cholesterol, HDL-cholesterol and BMI at baseline (0-15 months before the training) and after 0-5, 5-10 and 10-20 months.

RESULTS

A transient decrease of HbA1c (0.2%, 95% CI: 0.04-0.37, P = 0.017) and LDL-cholesterol levels (9.95 mg/dl, 95% CI: 2.24-17.76, P = 0.013) between baseline and the first follow-up examination was observed in the group overall. Thereafter, HbA1c and LDL-cholesterol were similar to baseline, whereas a persistent increase in HDL-cholesterol (P = 0.025) was evident in the multivariable analysis. No changes in BMI were observed. A significant type-by-time interaction (P = 0.008) in HbA1c suggests a long-term benefit in glycemic control in patients with type 2 diabetes.

CONCLUSION

A diabetes training program for intensive insulin therapy with particular emphasis on self-management skills was followed by a moderate and transient improvement of glycemic control and LDL-cholesterol and by a persistent increase in HDL-cholesterol. Long-term improvement in glycemic control was observed only in patients with type 2 diabetes.

Polycystic ovary syndrome and weight management

Polycystic ovary syndrome (PCOS) is a common condition in women of reproductive age, and has reproductive, metabolic and psychological implications. Weight gain and obesity worsen the features of PCOS, while weight loss improves the features of PCOS. While there are potential barriers to successful weight management in young women who do not suffer from PCOS, women with PCOS may experience additional barriers. Weight management strategies in younger women with or without PCOS should encompass both the prevention of excess weight gain and achieving and maintaining a reduced weight through multidisciplinary lifestyle management, comprising dietary, exercise and behavioral therapy, as well as attention to psychosocial stress and practical and physiological barriers to weight management. Further research is warranted in the examination of specific barriers to weight management in women with PCOS, as well as in the determination of optimal components of lifestyle weight management interventions in young women in order to facilitate long-term compliance.

The prevalence of abnormal eating behaviour in a representative sample of the French diabetic population

AIM

To assess the relationship between abnormal eating behaviour (AEB) and diabetes in a sample of French adult patients with type 1 (T1D) and type 2 (T2D) diabetes.

METHODS

Ninety-four consecutively recruited patients self-completed a series of validated questionnaires.

RESULTS

Over one-fourth of men with T1D (26%) or T2D (27%) and 11% of female T2D patients reported consistent and pathological overeating or binge-eating during the previous six months. Glycaemic control in these T1D patients was poorer than in T1D patients defined as normal eaters (NORM) (11.9% versus 9.6%), but did not reach statistical significance (P=0.08), and no significant difference was observed in the T2D group (P=0.61) either. T2D patients reported being markedly more restrained when eating than did the T1D patients (P=0.002), and their restraint increased along with their BMI (P<0.001). Patients who overate or binged also reported greater general hunger (P=0.02) and disinhibition (P=0.003) than did the NORM patients.

CONCLUSION

AEB is present in French diabetic patients at levels that are probably higher than among the general population. These results highlight the need for: (1) greater awareness among diabetes clinicians of the problem; (2) regular screening of diabetic patients for AEB; and (3) adaptation of therapeutic and dietary recommendations for this patient subgroup.