Abdominal obesity and physical inactivity as risk factors for NIDDM and impaired glucose tolerance in Indian, Creole, and Chinese Mauritians

Higher Visceral and Lower Peripheral Adiposity Characterize Fat Distribution and Insulin Resistance in Asian Indian Women with Polycystic Ovary Syndrome in Mauritius

INTRODUCTION

There are controversies about whether women with polycystic ovary syndrome (PCOS) show a disproportionately higher visceral adiposity, and its relevance to their higher cardiometabolic risks. We investigated in women of Asian Indian descent in Mauritius, a population inherently prone to abdominal obesity, whether those with PCOS will show a more adverse cardiometabolic risk profile that could be explained by abnormalities in fat distribution.

METHODS

Young women newly diagnosed with PCOS (n = 25) were compared with a reference control cohort (n = 139) for the following measurements made after an overnight fast: body mass index (BMI), waist circumference (WC), body composition by dual-energy X-ray absorptiometry, and blood pressure and blood assays for glycemic (glucose, HbA1c, and insulin) and lipid (triglycerides and cholesterols) profiles.

RESULTS

Women with PCOS showed, on average, higher BMI, WC, fat mass and lean mass (p < 0.01) than controls, but linear regression analyses indicate that for the same BMI (or same WC), the two groups showed no significant differences in fat mass and lean mass. By contrast, linear regression plots indicate that for the same total fat mass, women with PCOS showed higher trunk, android, and visceral fat (p < 0.01); no difference in abdominal subcutaneous fat; and lower peripheral (gynoid or limb) fat (p < 0.05). Furthermore, women with PCOS showed higher fasting plasma insulin, insulin resistance (HOMA-IR) index, and lower insulin sensitivity index (QUICKI) (all p < 0.001), which were completely or markedly abolished after adjusting for visceral fat or central-to-peripheral fat ratios.

CONCLUSION

In Mauritius, young women of Asian Indian descent with PCOS show altered fat distribution characterized by a disproportionately higher visceral (hazardous) adiposity in parallel to lower peripheral (protective) adiposity, which together explain their exacerbated state of hyperinsulinemia and insulin resistance.

Serum alanine transaminase is predictive of fasting and postprandial insulin and glucagon concentrations in type 2 diabetes

The liver plays a key role in glucose homeostasis. Serum liver enzyme levels, including alanine transaminase (ALT), aspartate transaminase (AST) and gamma-glutamyl transferase (GGT), are reportedly predictive of the risk of type 2 diabetes (T2D). However, the link between the liver enzyme profile and metabolic derangements in T2D, particularly the secretion of both insulin and glucagon, is not clear. This study evaluated its relationships with glycemia, insulin and glucagon both during fasting and after an oral glucose load or a mixed meal in T2D. 15 healthy and 43 T2D subjects ingested a 75 g glucose drink. 86 T2D subjects consumed a mixed meal. Venous blood was sampled for measurements of blood glucose and plasma insulin, C-peptide and glucagon. Blood glucose, plasma insulin, C-peptide and glucagon concentrations, both fasting and after oral glucose, correlated directly with ALT, while fewer and weaker correlations were observed with GGT or AST. Subgroup analysis in T2D subjects ascertained that plasma insulin, C-peptide and glucagon concentrations after oral glucose were higher with increasing ALT. Similar findings were observed in the T2D subjects who received a mixed meal. In conclusion, serum liver enzyme profile, particularly ALT, reflects dysregulated fasting and nutrient-stimulated plasma insulin and glucagon concentrations in T2D.

The Impact of Westernization on the Insulin/IGF-I Signaling Pathway and the Metabolic Syndrome: It Is Time for Change

The metabolic syndrome is a cluster of overlapping conditions resulting in an increased incidence of type 2 diabetes, cardiovascular disease, and cancer. In the last few decades, prevalence of the metabolic syndrome in the Western world has reached epidemic proportions and this is likely due to alterations in diet and the environment as well as decreased physical activity. This review discusses how the Western diet and lifestyle (Westernization) has played an important etiological role in the pathogenesis of the metabolic syndrome and its consequences by exerting negative effects on activity of the insulin-insulin-like growth factor-I (insulin-IGF-I) system. It is further proposed that interventions that normalize/reduce activity of the insulin-IGF-I system may play a key role in the prevention and treatment of the metabolic syndrome. For successful prevention, limitation, and treatment of the metabolic syndrome, the focus should be primarily on changing our diets and lifestyle in accordance with our genetic make-up, formed in adaptation to Paleolithic diets and lifestyles during a period of several million years of human evolution. Translating this insight into clinical practice, however, requires not only individual changes in our food and lifestyle, starting in pediatric populations at a very young age, but also requires fundamental changes in our current health systems and food industry. Change is needed: primary prevention of the metabolic syndrome should be made a political priority. New strategies and policies should be developed to stimulate and implement behaviors encouraging the sustainable use of healthy diets and lifestyles to prevent the metabolic syndrome before it develops.

'Diabetes doesn't matter as long as we're keeping traditions alive': a qualitative study exploring the knowledge and awareness of Type 2 diabetes and related risk factors amongst the young Punjabi Sikh population in the UK

Objectives: It is well known that Sikhs are at an increased risk of Type 2 Diabetes (T2DM) due to a genetic predisposition. High level of education is associated with lower incidence of T2DM. Young Sikhs are well educated compared to other South Asian sub-groups. Despite this, T2DM rates remain high in Sikhs. The uptake of preventative services is also low within Sikhs. At present, no research has been conducted with the young Punjabi Sikh population on diabetes awareness in the UK. To address this gap, this study explores the knowledge and awareness of T2DM and related modifiable risk factors in the UK Punjabi Sikh community. Views surrounding T2DM health-seeking behaviours are also explored.Design: A qualitative design comprising of 1-to-1 semi-structured interviews was adopted. Thirteen Punjabi Sikh participants between the ages of 18-30 took part. Participants were recruited through a Sikh temple and University of Manchester Sikh Society using purposive and snowball sampling in West Yorkshire and North West England. Data were analysed using inductive thematic analysis taking a critical realist stance.Results: Three themes were identified: (1) Perceptions of the causes of T2DM, (2) Perceptions of factors impacting physical activity and diet, and (3) Attitudes towards health-seeking behaviours.Conclusions: The findings show that although well educated, participants overlooked physical activity as contributing factor towards T2DM onset. Additionally, gender and cultural norms influenced physical activity and diet, as these are passed through generations to preserve the collectivist Sikh culture. Exploration of health seeking behaviours also found young Punjabi Sikhs perceived the internet to be the preferred tool to seek T2DM information. These findings hold implications for health professionals, as the information and preventative services provided to Sikhs can be tailored to be culturally appropriate and in line with cultural and gender norms, such as bhangra dancing for physical activity.

Age-friendly neighbourhoods and physical activity of older Surinamese individuals in Rotterdam, the Netherlands

BACKGROUND

Age-friendly neighbourhoods seem to promote physical activity among older individuals. Physical activity is especially important for chronically ill individuals. In the Netherlands, older Surinamese individuals are more likely to have chronic diseases than are their native Dutch counterparts. This study examined relationships of neighbourhood characteristics with physical activity among older Surinamese individuals in Rotterdam, the Netherlands.

METHODS

Of 2749 potential participants, 697 (25%) community-dwelling older (age ≥ 70 years) Surinamese individuals living in Rotterdam, the Netherlands, completed a questionnaire on personal and neighbourhood characteristics between March and June 2020. Correlation and multilevel regression analyses were performed to identify associations between missing neighbourhood characteristics for ageing in place and physical activity.

RESULTS

Scores for the neighbourhood domains communication and information (r = -0.099, p ≤ 0.05), community support and health services (r = -0.139, p ≤ 0.001), and respect and social inclusion (r = -0.141, p ≤ 0.001), correlated negatively with participants' PA. In the multilevel analysis, overall missing neighbourhood characteristics to age in place scores were associated negatively with physical activity (p ≤ 0.05).

CONCLUSION

This study showed the importance of age-friendly neighbourhoods for physical activity among older Surinamese individuals in Rotterdam, the Netherlands. Our findings suggest that the neighbourhood plays an important role in supporting older individuals' leading of physically active lifestyles. Further research is needed to support the development of interventions to create age-friendly neighbourhoods.

Development of type 2 diabetes mellitus in people with intermediate hyperglycaemia

BACKGROUND

Intermediate hyperglycaemia (IH) is characterised by one or more measurements of elevated blood glucose concentrations, such as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and elevated glycosylated haemoglobin A1c (HbA1c). These levels are higher than normal but below the diagnostic threshold for type 2 diabetes mellitus (T2DM). The reduced threshold of 5.6 mmol/L (100 mg/dL) fasting plasma glucose (FPG) for defining IFG, introduced by the American Diabetes Association (ADA) in 2003, substantially increased the prevalence of IFG. Likewise, the lowering of the HbA1c threshold from 6.0% to 5.7% by the ADA in 2010 could potentially have significant medical, public health and socioeconomic impacts.

OBJECTIVES

To assess the overall prognosis of people with IH for developing T2DM, regression from IH to normoglycaemia and the difference in T2DM incidence in people with IH versus people with normoglycaemia.

SEARCH METHODS

We searched MEDLINE, Embase, ClincialTrials.gov and the International Clinical Trials Registry Platform (ICTRP) Search Portal up to December 2016 and updated the MEDLINE search in February 2018. We used several complementary search methods in addition to a Boolean search based on analytical text mining.

SELECTION CRITERIA

We included prospective cohort studies investigating the development of T2DM in people with IH. We used standard definitions of IH as described by the ADA or World Health Organization (WHO). We excluded intervention trials and studies on cohorts with additional comorbidities at baseline, studies with missing data on the transition from IH to T2DM, and studies where T2DM incidence was evaluated by documents or self-report only.

DATA COLLECTION AND ANALYSIS

One review author extracted study characteristics, and a second author checked the extracted data. We used a tailored version of the Quality In Prognosis Studies (QUIPS) tool for assessing risk of bias. We pooled incidence and incidence rate ratios (IRR) using a random-effects model to account for between-study heterogeneity. To meta-analyse incidence data, we used a method for pooling proportions. For hazard ratios (HR) and odds ratios (OR) of IH versus normoglycaemia, reported with 95% confidence intervals (CI), we obtained standard errors from these CIs and performed random-effects meta-analyses using the generic inverse-variance method. We used multivariable HRs and the model with the greatest number of covariates. We evaluated the certainty of the evidence with an adapted version of the GRADE framework.

MAIN RESULTS

We included 103 prospective cohort studies. The studies mainly defined IH by IFG5.6 (FPG mmol/L 5.6 to 6.9 mmol/L or 100 mg/dL to 125 mg/dL), IFG6.1 (FPG 6.1 mmol/L to 6.9 mmol/L or 110 mg/dL to 125 mg/dL), IGT (plasma glucose 7.8 mmol/L to 11.1 mmol/L or 140 mg/dL to 199 mg/dL two hours after a 75 g glucose load on the oral glucose tolerance test, combined IFG and IGT (IFG/IGT), and elevated HbA1c (HbA1c5.7: HbA1c 5.7% to 6.4% or 39 mmol/mol to 46 mmol/mol; HbA1c6.0: HbA1c 6.0% to 6.4% or 42 mmol/mol to 46 mmol/mol). The follow-up period ranged from 1 to 24 years. Ninety-three studies evaluated the overall prognosis of people with IH measured by cumulative T2DM incidence, and 52 studies evaluated glycaemic status as a prognostic factor for T2DM by comparing a cohort with IH to a cohort with normoglycaemia. Participants were of Australian, European or North American origin in 41 studies; Latin American in 7; Asian or Middle Eastern in 50; and Islanders or American Indians in 5. Six studies included children and/or adolescents.Cumulative incidence of T2DM associated with IFG5.6, IFG6.1, IGT and the combination of IFG/IGT increased with length of follow-up. Cumulative incidence was highest with IFG/IGT, followed by IGT, IFG6.1 and IFG5.6. Limited data showed a higher T2DM incidence associated with HbA1c6.0 compared to HbA1c5.7. We rated the evidence for overall prognosis as of moderate certainty because of imprecision (wide CIs in most studies). In the 47 studies reporting restitution of normoglycaemia, regression ranged from 33% to 59% within one to five years follow-up, and from 17% to 42% for 6 to 11 years of follow-up (moderate-certainty evidence).Studies evaluating the prognostic effect of IH versus normoglycaemia reported different effect measures (HRs, IRRs and ORs). Overall, the effect measures all indicated an elevated risk of T2DM at 1 to 24 years of follow-up. Taking into account the long-term follow-up of cohort studies, estimation of HRs for time-dependent events like T2DM incidence appeared most reliable. The pooled HR and the number of studies and participants for different IH definitions as compared to normoglycaemia were: IFG5.6: HR 4.32 (95% CI 2.61 to 7.12), 8 studies, 9017 participants; IFG6.1: HR 5.47 (95% CI 3.50 to 8.54), 9 studies, 2818 participants; IGT: HR 3.61 (95% CI 2.31 to 5.64), 5 studies, 4010 participants; IFG and IGT: HR 6.90 (95% CI 4.15 to 11.45), 5 studies, 1038 participants; HbA1c5.7: HR 5.55 (95% CI 2.77 to 11.12), 4 studies, 5223 participants; HbA1c6.0: HR 10.10 (95% CI 3.59 to 28.43), 6 studies, 4532 participants. In subgroup analyses, there was no clear pattern of differences between geographic regions. We downgraded the evidence for the prognostic effect of IH versus normoglycaemia to low-certainty evidence due to study limitations because many studies did not adequately adjust for confounders. Imprecision and inconsistency required further downgrading due to wide 95% CIs and wide 95% prediction intervals (sometimes ranging from negative to positive prognostic factor to outcome associations), respectively.This evidence is up to date as of 26 February 2018.

AUTHORS' CONCLUSIONS

Overall prognosis of people with IH worsened over time. T2DM cumulative incidence generally increased over the course of follow-up but varied with IH definition. Regression from IH to normoglycaemia decreased over time but was observed even after 11 years of follow-up. The risk of developing T2DM when comparing IH with normoglycaemia at baseline varied by IH definition. Taking into consideration the uncertainty of the available evidence, as well as the fluctuating stages of normoglycaemia, IH and T2DM, which may transition from one stage to another in both directions even after years of follow-up, practitioners should be careful about the potential implications of any active intervention for people 'diagnosed' with IH.

Predictors of Hypertension in Mauritians with Normotension and Prehypertension at Baseline: A Cohort Study

Information on the predictors of future hypertension in Mauritians with prehypertension is scant. The aim of this study was to analyze the 5-year and 11-year risk of hypertension and its predictors in people with normotension and prehypertension at baseline in Mauritius in 1987. This was a retrospective cohort study of 883 men and 1194 women of Mauritian Indian and Mauritian Creole ethnicity, aged 25–74 years old, free of hypertension at baseline in 1987 with follow-up examinations in 1992 and 1998 using the same methodology. The main outcome was 5- and 11-year risk of hypertension. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were calculated. The 5-year risk of hypertension was 5.4-times higher in people with prehypertension compared with normotensive individuals at baseline. The corresponding odds for prehypertensive people at baseline regarding 11-year hypertension risk was 3.39 (95% CI 2.67–4.29) in the adjusted logistic regression models. Being of Creole ethnicity (OR 1.42; 95% CI 1.09–1.86) increased the 11-year odds of hypertension compared with the Indian population. It is of importance to screen for people with prehypertension and implement strategies to reduce their systolic blood pressure levels to the recommended levels of 120/80 mmHg. Special attention needs to be given to Mauritians of Creole ethnicity.

Longitudinal patterns in objective physical activity and sedentary time in a multi-ethnic sample of children from the UK

BACKGROUND

Children of South Asian decent born in the UK display lower levels of physical activity than British Caucasians although no longitudinal data are available.

OBJECTIVES

We aimed to investigate change in activity levels over 1 year in a diverse ethnic sample of children residing in London, UK.

METHODS

Children were categorized into ethnic groups (Caucasian/mixed, Black, South Asian). At baseline and 1-year follow-up, children's objective physical activity was monitored (Actigraph accelerometer) for at least 1 day. Mixed models were employed to investigate differences in change in activity levels between ethnic groups.

RESULTS

A total of 281 children were included in the analyses. South Asians had a significantly greater increase in time spent sedentary at follow-up than those of a Caucasian/mixed ethnicity (B [ratio sedentary/wear time] = 0.024; 95% confidence interval 0.003, 0.046). South Asian children recorded lower moderate to vigorous physical activity at baseline (B = -6.5, 95% confidence interval, -11.1, -1.9 min d^-1 , p = 0.006) although levels remained relatively stable over follow-up and changes did not differ across ethnic group.

CONCLUSIONS

In a diverse ethnic sample of children from inner city London, those of a South Asian ethnicity exhibited a significantly greater increase in sedentary time over a period of 12 months in comparison with Caucasian/mixed and Black children.

Association of obesity with hypertension and type 2 diabetes mellitus in India: A meta-analysis of observational studies

AIM

To perform a meta-analysis of the association of obesity with hypertension and type 2 diabetes mellitus (T2DM) in India among adults.

METHODS

To conduct meta-analysis, we performed comprehensive, electronic literature search in the PubMed, CINAHL Plus, and Google Scholar. We restricted the analysis to studies with documentation of some measure of obesity namely; body mass index, waist-hip ratio, waist circumference and diagnosis of hypertension or diagnosis of T2DM. By obtaining summary estimates of all included studies, the meta-analysis was performed using both RevMan version 5 and “metan” command STATA version 11. Heterogeneity was measured by I² statistic. Funnel plot analysis has been done to assess the study publication bias.

RESULTS

Of the 956 studies screened, 18 met the eligibility criteria. The pooled odds ratio between obesity and hypertension was 3.82 (95%CI: 3.39 to 4.25). The heterogeneity around this estimate (I2 statistic) was 0%, indicating low variability. The pooled odds ratio from the included studies showed a statistically significant association between obesity and T2DM (OR = 1.14, 95%CI: 1.04 to 1.24) with a high degree of variability.

CONCLUSION

Despite methodological differences, obesity showed significant, potentially plausible association with hypertension and T2DM in studies conducted in India. Being a modifiable risk factor, our study informs setting policy priority and intervention efforts to prevent debilitating complications.

Temporal trends in the prevalence of diabetes mellitus in a rural community in Sri Lanka

In developing countries the prevalence of diabetes mellitus is reported to be lower in rural areas compared to urban areas. This difference has been attributed to lifestyle factors associated with the higher socio-economic status of those living in urban areas. However, recent clinical observations indicate that the prevalence of diabetes is on the increase even in the rural sector. The aims of the present study were to objectively assess whether the prevalence of diabetes has increased in a named rural community in Sri Lanka during a period of ten years and whether there has been a change in the socio-economic status of the community during this period. The study was conducted on a sample of 220 subjects randomly selected from an adult population of 25,605 residents in a rural area in central Sri Lanka. Each of these subjects had the fasting blood sugar estimated and the height, weight, resting blood pressure and socio-economic parameters, such as the level of education, occupation and monthly income, recorded. These data were compared with those of a similar study conducted by the main author in the same community ten years ago.

The results revealed that the age-standardised prevalence of diabetes had increased from 2.5% in 1990 to 8.5% in 2000 (p=0.008) and that this was accompanied by an increase in the monthly income, level of education and body mass indices. Since nearly 70% of all Sri Lankans live in villages, continuation of the present trend would result in a dramatic increase in the number of patients with diabetes in the future. Suitable strategies should be implemented to arrest this trend and manage a large number of patients with diabetes in the future.

Anaesthesia and the patient with diabetes

AIMS

To provide updated knowledge regarding the airway management and the possibility of difficult intubation in diabetic patients.

MATERIALS AND METHODS

We preformed a systematic literature review of the English language literature, published over the past 10 years which deals with this subject.

RESULTS

The vast majority of the modern literature data supports the fact that diabetic population has higher risk for difficult intubation occurrence. The most important characteristics of diabetic patients that are considered to be contributing factors for the difficult intubation are obesity, increased neck circumference and stiff joint syndrome.

CONCLUSION

A special attention and thorough preoperative preparation should be given to patients with diabetes. In order to predict and prevent difficult intubation in these patients, further studies are needed to investigate this issue closely.

Detrimental and protective fat: body fat distribution and its relation to metabolic disease

Obesity is linked to numerous comorbidities that include, but are not limited to, glucose intolerance, insulin resistance, dyslipidemia, and cardiovascular disease. Current evidence suggests, however, obesity itself is not an exclusive predictor of metabolic dysregulation but rather adipose tissue distribution. Obesity-related adverse health consequences occur predominately in individuals with upper body fat accumulation, the detrimental distribution, commonly associated with visceral obesity. Increased lower body subcutaneous adipose tissue, however, is associated with a reduced risk of obesity-induced metabolic dysregulation and even enhanced insulin sensitivity, thus, storage in this region is considered protective. The proposed mechanisms that causally relate the differential outcomes of adipose tissue distribution are often attributed to location and/or adipocyte regulation. Visceral adipose tissue effluent to the portal vein drains into the liver where hepatocytes are directly exposed to its metabolites and secretory products, whereas the subcutaneous adipose tissue drains systemically. Adipose depots are also inherently different in numerous ways such as adipokine release, immunity response and regulation, lipid turnover, rate of cell growth and death, and response to stress and sex hormones. Proximal extrinsic factors also play a role in the differential drive between adipose tissue depots. This review focuses on the deleterious mechanisms postulated to drive the differential metabolic response between central and lower body adipose tissue distribution.

The role of visceral and subcutaneous adipose tissue fatty acid composition in liver pathophysiology associated with NAFLD

Visceral adiposity is associated with type-2-diabetes, inflammation, dyslipidemia and non-alcoholic fatty liver disease (NAFLD), whereas subcutaneous adiposity is not. We hypothesized that the link between visceral adiposity and liver pathophysiology involves inherent or diet-derived differences between visceral and subcutaneous adipose tissue to store and mobilize saturated fatty acids. The goal of the present study was to characterize the fatty acid composition of adipose tissue triglyceride and portal vein fatty acids in relation to indices of liver dysregulation. For 8 weeks rats had free access to control (CON; 12.9% corn/safflower oil; 3.6 Kcal/g), high saturated fat (SAT; 45.2% cocoa butter; 4.5 Kcal/g) or high polyunsaturated fat (PUFA; 45.2% safflower oil; 4.5 Kcal/g) diets. Outcome measures included glucose tolerance, visceral and subcutaneous adipose tissue triglyceride, liver phospholipids and plasma (portal and systemic) free fatty acid composition, indices of inflammation and endoplasmic reticulum stress in the liver and adipose tissue depots and circulating adipo/cytokines. Hepatic triglycerides were significantly increased in both high fat diet groups compared to control and were significantly higher in PUFA compared to SAT. Although glucose tolerance was not different among diet groups, SAT increased markers of inflammation and ER stress in the liver and both adipose tissue depots. Fatty acid composition did not differ among adipose depots or portal blood in any dietary group. Overall, these data suggest that diets enriched in saturated fatty acids are associated with liver inflammation, ER stress and injury, but that any link between visceral adipose tissue and these liver indices does not involve selective changes to fatty acid composition in this depot or the portal vein.

Obesity and type 2 diabetes in Sub-Sahara Africa

There is a mounting body of evidence regarding the challenge posed by diabetes and obesity on the health systems of many Sub-Sahara African countries. This trend has been linked to the changing demographic profile together with rapid urbanization and changing lifestyles in both rural and urban settings in Africa. Africa is expected to witness the greatest increase in the number of people with diabetes from 19.8 million in 2013 to 41.4 million in 2035 if current trends persist. Excess weight alone currently accounts for at least 2.8 million deaths globally each year through increased risk for type 2 diabetes and cardiovascular complications. This review highlights recent literature on the problem of obesity and type 2 diabetes in Sub-Sahara Africa. It exposes the need for concrete interventions based on the now available wealth of evidence.

Joint Association of Dietary Pattern and Physical Activity Level with Cardiovascular Disease Risk Factors among Chinese Men: A Cross-Sectional Study

The purpose of this cross-sectional study was to investigate the joint associations of physical activity level (PAL) and dietary patterns in relation to cardiovascular disease (CVD) risk factors among Chinese men. The study population consisted of 13 511 Chinese males aged 18–59 years from the 2002 China National Nutrition and Health Survey. Based on dietary data collected by a food frequency questionnaire, four dietary patterns were identified and labeled as “Green Water” (high consumption of rice, vegetables, seafood, pork, and poultry), “Yellow Earth” (high consumption of wheat flour products and starchy tubers), “New Affluent” (high consumption of animal sourced foods and soybean products), and “Western Adopter” (high consumption of animal sourced foods, cakes, and soft drinks). From the information collected by a 1-year physical activity questionnaire, PAL was calculated and classified into 4 categories: sedentary, low active, active, and very active. As compared with their counterparts from the New Affluent pattern, participants who followed the Green Water pattern had a lower likelihood of abdominal obesity (AO; 50.2%), hypertension (HT; 37.9%), hyperglycemia (HG; 41.5%), elevated triglyceride (ETG; 14.5%), low HDL (LHDL; 39.8%), and metabolic syndrome (MS; 51.9%). When compared to sedentary participants, the odds ratio of participants with very active PAL was 0.62 for AO, 0.85 for HT, 0.71 for HG, 0.76 for ETG, 0.74 for LHDL, and 0.58 for MS. Individuals who followed both very active PAL and the Green Water pattern had a lower likelihood of CVD risk factors (AO: 65.8%, HT: 39.1%, HG: 57.4%, ETG: 35.4%, LHDL: 56.1%, and MS: 75.0%), compared to their counterparts who followed both sedentary PAL and the New Affluent pattern. In addition, adherence to both healthy dietary pattern and very active PAL presented a remarkable potential for CVD risk factor prevention.

Web-based family intervention for overweight children: a pilot study

BACKGROUND

Research has shown the efficacy of family-based behavioral interventions for overweight children, but a major difficulty is access to effective treatment programs. The objective of this study was to develop and test the initial feasibility and efficacy of a web-based family program for overweight 8- to 12-year-old children.

METHODS

A website was created using concepts from effective family-based behavioral programs and input from focus groups with overweight children, parents, and pediatricians. The website provided information about obesity and healthy lifestyles, assessment of dietary and physical activity habits, interactive dietary and physical activity games, and instruction in goal-setting and monitoring of goals. Children selected a dietary and physical activity goal and a daily step goal with pedometers. Feasibility and pilot testing over 4 weeks was conducted with 24 overweight children referred by a physician. Outcomes were z-BMI, healthy eating and physical activity, and intrinsic motivation and self-efficacy for weight control.

RESULTS

Mean number of logins over the study period was 11.4 for the study sample. Eighteen families (75%) returned for the follow-up assessment. Pre-post analyses for these participants showed improvements in intrinsic motivation, (p=0.05), self-efficacy (p=0.025), physical activity (p=0.005), and healthy lifestyle behaviors (p=0.001). Comparisons between high and low users of the program indicated that high users reduced their BMI while low users increased their BMI over time (p=0.02); high users also improved their dietary intake relative to low users (p=0.04). Consumer satisfaction ratings were high.

CONCLUSION

These pilot findings suggest this is a feasible approach for treatment of overweight children and that children who used the web program frequently improved their BMI and dietary intake.

Physical activity reduces risk for colon polyps in a multiethnic colorectal cancer screening population

Background

Identifying modifiable factors that influence the epidemiology of colorectal cancer incidence among multiethnic groups might be informative for the development of public health strategies targeting the disease. Minimal data exists describing the impact of physical activity on colorectal polyp risk in United States minority populations. The aim of this study is to evaluate the relationship of exercise on the prevalence of polyps in a multiethnic colorectal cancer screening population.

Results

We enrolled 982 patients: 558 Hispanic, 202 Asian,149 Black, and 69 White. Patients who reported exercising one or more hours weekly had a lower prevalence of any polyps (25.3% vs 33.2%, P = 0.008) as well as adenomas (13.8 vs. 18.9%, P = 0.03) compared to those who did not exercise. Black and Hispanic patients and those who were overweight or obese also had lower prevalence of polyps if they led an active lifestyle. Multivariate analysis revealed that age >55, male sex, and Black race/ethnicity were positively associated with the presence of adenomas, while a history of exercising one hour or more weekly was an independent negative predictor for the presence of adenomas anywhere in the colon (OR 0.67; 95% CI 0.4 - 0.9, P = 0.03).

Conclusions

Exercising one hour per week was associated with a lower prevalence of polyps and adenomas when compared to those who exercised less or not at all. An active lifestyle provides benefits to groups who are at risk for colorectal cancer, such as Blacks. It also provides significant protection to overweight and obese individuals. Public health initiatives should promote physical activity as a cancer prevention tool in multiethnic populations.

Trial registration

none

The influence of hip circumference on the relationship between abdominal obesity and mortality

BACKGROUND

Higher waist circumference and lower hip circumference are both associated with increased cardiovascular disease (CVD) risk, despite being directly correlated. The real effects of visceral obesity may therefore be underestimated when hip circumference is not fully taken into account. We hypothesized that adding waist and hip circumference to traditional risk factors would significantly improve CVD risk prediction.

METHODS

In a population-based survey among South Asian and African Mauritians (n = 7978), 1241 deaths occurred during 15 years of follow-up. In a model that included variables used in previous CVD risk calculations (a Framingham-type model), the association between waist circumference and mortality was examined before and after adjustment for hip circumference. The percentage with an increase in estimated 10-year cumulative mortality of >25% and a decrease of >20% after waist and hip circumference were added to the model was calculated.

RESULTS

Waist circumference was strongly related to mortality only after adjustment for hip circumference and vice versa. Adding waist and hip circumference to a Framingham-type model increased estimated 10-year cumulative CVD mortality by >25% for 23.7% of those who died and 15.7% of those censored. Cumulative mortality decreased by >20% for 4.5% of those who died and 14.8% of those censored.

CONCLUSIONS

The effect of central obesity on mortality risk is seriously underestimated without adjustment for hip circumference. Adding waist and hip circumference to a Framingham-type model for CVD mortality substantially increased predictive power. Both may be important inclusions in CVD risk prediction models.

A Cross-Sectional Analysis of the Association between Physical Activity and Visceral Adipose Tissue Accumulation in a Multiethnic Cohort

Higher levels of VAT at the same body size and lower levels of physical activity (PA) have been reported in persons of Chinese and South Asian origin compared to European origin. The purpose of this study was to test the hypothesis that higher levels of VAT in persons of Chinese and South Asian origin versus European origin are associated with lower levels of PA. Chinese, European, and South Asian participants were assessed for sociodemographics, obesity-related measures, anthropometrics, and PA. Bivariate correlations, analysis of covariance, and regression models were used to explore ethnic differences in PA and the role of PA in explaining obesity-related measures. We observed ethnic differences in both body fat distribution and PA. Chinese and South Asians had higher amounts of VAT at a given BMI but lower amounts of moderate PA, vigorous PA, and moderate-to-vigorous PA (MVPA). Furthermore, we found ethnic-specific differences in the associations between body fat distribution and PA with only Europeans showing a consistent negative relationship between body fat distribution and PA. When ethnic differences in PA were taken into account, there were no longer any differences in VAT between the Chinese and European groups, while VAT remained higher in South Asians than Europeans.

Prevalence, risk factors and complications associated with type 2 diabetes in migrant South Asians

It is estimated that type 2 diabetes (T2D) currently affects about 246 million people worldwide, with South Asians, especially Indians, having both the largest number of cases and the fastest growing prevalence. South Asian ethnicity has been identified as a major risk factor for the development of T2D with central adiposity, insulin resistance and an unfavourable lipid profile being identified as predominant signals of alarm. Leading databases, including Web of Science, Medline, PubMed and Science Direct, were consulted and manual searches were conducted for cited references in leading diabetes-related journals. In all, 152 articles were included for the final assessment reported in this review. Genetic predisposition, central adiposity and unfavourable lifestyle, including physical inactivity and an unhealthy diet, were associated with the prevalence of T2D in migrant South Asians. 'Westernization', acculturation, socio-economic factors and lack of knowledge about the disease have also been identified as contributors to the development of T2D in this population. Higher prevalence of T2D in migrant South Asians may not be entirely attributed to genetic predisposition; hence, ethnicity and associated modifiable risk factors need further investigation. Preventive measures and appropriate interventions are currently limited by the lack of ethnic-specific cut-off points for anthropometric and biological markers, as well as by the absence of reliable methods for dietary and physical activity assessment. This article describes the prevalence rate, risk factors and complications associated with T2D in migrant South Asians living in different countries.

Cut-points for waist circumference in Europids and South Asians

There is little strong evidence that currently recommended higher waist circumference cut-points for Europids compared with South Asians are associated with similar risk for type 2 diabetes. This study was designed to provide such evidence. Longitudinal studies over 5 years were conducted among 5,515 Europid and 2,214 ethnically South Asian participants. Age-standardized diabetes incidence at different levels of waist circumference and incidence difference relative to a reference value were calculated. The Youden Index was used to determine waist circumference cut-points. At currently recommended cut-points, estimated annual diabetes incidence for a 50-year-old Europid was <0.6% for both sexes, and for a 50-year-old South Asian, 5.8% for men and 2.1% for women. Annual diabetes incidence of 1% was observed for a 50 year old at a waist circumference 35-40 cm greater in Europid compared to South Asian men and women. Incidence difference between recommended cut-points and a reference value (80 cm in men, 70 cm in women) was 0.3 and 4.4% per year for Europid and South Asian men, and 0.2 and 0.8% per year for Europid and South Asian women, respectively. Waist circumference cut-points chosen using the Youden Index were shown to be dependent on obesity levels in the population. The much higher observed risk of diabetes in South Asians compared to Europids at the respective recommended waist circumference cut-points suggests that differences between them should be greater. Approaches that use the Youden Index to select waist circumference cut-points are inappropriate and should not be used for this purpose.

Primary prevention of colorectal cancer

Colorectal cancer has been strongly associated with a Western lifestyle. In the past several decades, much has been learned about the dietary, lifestyle, and medication risk factors for this malignancy. Although there is controversy about the role of specific nutritional factors, consideration of dietary pattern as a whole appears useful for formulating recommendations. For example, several studies have shown that high intake of red and processed meats, highly refined grains and starches, and sugars is related to increased risk of colorectal cancer. Replacing these factors with poultry, fish, and plant sources as the primary source of protein; unsaturated fats as the primary source of fat; and unrefined grains, legumes and fruits as the primary source of carbohydrates is likely to lower risk of colorectal cancer. Although a role for supplements, including vitamin D, folate, and vitamin B6, remains uncertain, calcium supplementation is likely to be at least modestly beneficial. With respect to lifestyle, compelling evidence indicates that avoidance of smoking and heavy alcohol use, prevention of weight gain, and maintenance of a reasonable level of physical activity are associated with markedly lower risks of colorectal cancer. Medications such as aspirin and nonsteroidal anti-inflammatory drugs and postmenopausal hormones for women are associated with substantial reductions in colorectal cancer risk, though their utility is affected by associated risks. Taken together, modifications in diet and lifestyle should substantially reduce the risk of colorectal cancer and could complement screening in reducing colorectal cancer incidence.

Risk prediction models for the development of diabetes in Mauritian Indians

AIMS

To develop risk prediction models of future diabetes in Mauritian Indians.

METHODS

Three thousand and ninety-four Mauritian Indians (1141 men, aged 20-65 years) without diabetes in 1987 or 1992 were followed up to 1992 or 1998. Subjects underwent repeated oral glucose tolerance tests and diabetes was diagnosed according to 2006 World Health Organization/International Diabetes Federation criteria. Cox regression models for interval censored data were performed using data from 1544 randomly selected participants. Predicted probabilities for diabetes were calculated and validated in the remaining 1550 subjects.

RESULTS

Over 11 years of follow-up, there were 511 cases of diabetes. Among variables tested, family history of diabetes, obesity (body mass index, waist circumference) and glucose were significant predictors of diabetes. Predicted probabilities derived from a simple model fitted with sex, family history of diabetes and obesity ranged from 0.05 to 0.64 in men and 0.03 to 0.49 in women. To predict the onset of diabetes, area under the receiver operating characteristic (ROC) curve (AROC) of predicted probabilities was 0.62 (95% confidence interval, 0.56-0.68) in men and 0.64 (0.59-0.69) in women. At a cut-off point of 0.12, the sensitivity and specificity were 0.72 (0.71-0.74) and 0.47 (0.45-0.49) in men and 0.77 (0.75-0.78) and 0.50 (0.48-0.52) in women, respectively. Addition of fasting plasma glucose (FPG) to the model improved the prediction slightly [AROC curve 0.70 (0.65-0.76) in men, 0.71 (0.67-0.76) in women].

CONCLUSIONS

A diabetes prediction model based on obesity and family history yielded moderate discrimination in Mauritian Indians, which was slightly inferior to the model with the FPG but may be useful in low-income countries to promote identification of people at high risk of diabetes.

Two-year results from a community-wide diabetes prevention intervention in a high risk indigenous community: the Ngati and Healthy project

We describe changes in markers and prevalence of glucose metabolism disorders following a 2-year community-wide intervention aimed at reducing insulin resistance (IR) prevalence in a high risk community. Surveys were undertaken before and 2 years after implementation of a community developed and led diabetes prevention program. Proportions and means were calculated and compared by sex and age groups: 25-49 years and 50+ years. A process evaluation contributed to interpretation of results. Response rates were around 50% and demographic characteristics similar in both surveys. Overall, IR prevalence decreased markedly from 35.5% to 25.4% (p=0.003). Most changes were observed amongst 25-49 years old women for whom there was a significant change in prevalences of IR and glucose metabolism disorders (p=0.015), largely due to reduced IR prevalence (38.2-25.6%). In 2006, 60.3% achieved minimum recommended exercise levels and 65.4% ate wholegrain bread compared with 45.1% (p=0.002) and 42.2% (p=0.044), respectively, in 2003. Participation in a community diabetes prevention intervention appeared to reduce IR prevalence after 2 years in those with the highest level of participation and most marked lifestyle changes.

Urban rural differences in prevalence of self-reported diabetes in India--the WHO-ICMR Indian NCD risk factor surveillance

Recent reports show strikingly high prevalence of diabetes among urban Asian Indians; however, there are very few studies comparing urban, peri-urban and rural prevalence rates of diabetes and their risk factors at the national level. This study is a part of the national non-communicable diseases (NCD) risk factor surveillance conducted in different geographical locations (North, South, East, West/Central) in India between April 2003 and March 2005. A total of 44,523 individuals (age: 15-64 years) inclusive of 15,239 from urban, 15,760 from peri-urban/slum and 13,524 from rural areas were recruited. Major risk factors were studied using modified WHO STEPS approach. Diabetes was diagnosed based on self-reported diabetes diagnosed by a physician. The lowest prevalence of self-reported diabetes was recorded in rural (3.1%) followed by peri-urban/slum (3.2%) and the highest in urban areas (7.3%, odds ratio (OR) for urban areas: 2.48, 95% confidence interval (CI): 2.21-2.79, p<0.001). Urban residents with abdominal obesity and sedentary activity had the highest prevalence of self-reported diabetes (11.3%) while rural residents without abdominal obesity performing vigorous activity had the lowest prevalence (0.7%). In conclusion, this nation-wide NCD risk factor surveillance study shows that the prevalence of self-reported diabetes is higher in urban, intermediate in peri-urban and lowest in rural areas. Urban residence, abdominal obesity and physical inactivity are the risk factors associated with diabetes in this study.

The metabolic syndrome as a predictor of incident diabetes mellitus in Mauritius

AIMS

To assess the utility of the metabolic syndrome (MetS) and a Diabetes Predicting Model as predictors of incident diabetes.

METHODS

A longitudinal survey was conducted in Mauritius in 1987 (n = 4972; response 80%) and 1992 (n = 3685; follow-up 74.2%). Diabetes status was retrospectively determined using 1999 World Health Organization (WHO) criteria. MetS was determined according to four definitions and sensitivity, positive predictive value (PPV), specificity and the association with incident diabetes before and after adjustment for MetS components calculated.

RESULTS

Of the 3198 at risk, 297 (9.2%) developed diabetes between 1987 and 1992. The WHO MetS definition had the highest prevalence (20.3%), sensitivity (42.1%) and PPV (26.8%) for prediction of incident diabetes, the strongest association with incident diabetes after adjustment for age and sex [odds ratio 4.6 (3.5-6.0)] and was the only definition to show a significant association after adjustment for its component parts (in men only). The low prevalence and sensitivity of the International Diabetes Federation (IDF) and ATPIII MetS definitions resulted from waist circumference cut-points that were high for this population, particularly in men, and both were not superior to a diabetes predicting model on receiver operating characteristic analysis.

CONCLUSIONS

Of the MetS definitions tested, the WHO definition best identifies those who go on to develop diabetes, but is not often used in clinical practice. If cut-points or measures of obesity appropriate for this population were used, the IDF and ATPIII MetS definitions could be recommended as useful tools for prediction of diabetes, given their relative simplicity.

Chemerin is a novel adipokine associated with obesity and metabolic syndrome

Soluble protein hormones are key regulators of a number of metabolic processes, including food intake and insulin sensitivity. We have used a signal sequence trap to identify genes that encode secreted or membrane-bound proteins in Psammomys obesus, an animal model of obesity and type 2 diabetes (T2D). Using this signal sequence trap, we identified the chemokine chemerin as being a novel adipokine. Gene expression of chemerin and its receptor, chemokine-like receptor 1 (CMKLR1), was significantly higher in adipose tissue of obese and type 2 diabetic P. obesus compared with lean, normoglycemic P. obesus. Fractionation of P. obesus adipose tissue confirmed that chemerin was predominantly expressed in adipocytes, whereas CMKLR1 was expressed in both adipocytes and stromal-vascular cells of adipose tissue. In 3T3-L1 adipocytes, chemerin was markedly induced during differentiation, whereas CMKLR1 was down-regulated during differentiation. Serum chemerin levels were measured by ELISA in human plasma samples from 114 subjects with T2D and 142 normal glucose tolerant controls. Plasma chemerin levels were not significantly different between subjects with T2D and normal controls. However, in normal glucose tolerant subjects, plasma chemerin levels were significantly associated with body mass index, circulating triglycerides, and blood pressure. Here we report, for the first time, that chemerin is an adipokine, and circulating levels of chemerin are associated with several key aspects of metabolic syndrome.

Dietary advice for treatment of type 2 diabetes mellitus in adults

BACKGROUND

While initial dietary management immediately after formal diagnosis is an 'accepted' cornerstone of treatment of type 2 diabetes mellitus, a formal and systematic overview of its efficacy and method of delivery is not currently available.

OBJECTIVES

To assess the effects of type and frequency of different types of dietary advice for adults with type 2 diabetes.

SEARCH STRATEGY

We carried out a comprehensive search of The Cochrane Library, MEDLINE, EMBASE, CINAHL, AMED, bibliographies and contacted relevant experts.

SELECTION CRITERIA

All randomised controlled trials, of six months or longer, in which dietary advice was the main intervention.

DATA COLLECTION AND ANALYSIS

The lead investigator performed all data extraction and quality scoring with duplication being carried out by one of the other six investigators independently with discrepancies resolved by discussion and consensus. Authors were contacted for missing data.

MAIN RESULTS

Thirty-six articles reporting a total of eighteen trials following 1467 participants were included. Dietary approaches assessed in this review were low-fat/high-carbohydrate diets, high-fat/low-carbohydrate diets, low-calorie (1000 kcal per day) and very-low-calorie (500 kcal per day) diets and modified fat diets. Two trials compared the American Diabetes Association exchange diet with a standard reduced fat diet and five studies assessed low-fat diets versus moderate fat or low-carbohydrate diets. Two studies assessed the effect of a very-low-calorie diet versus a low-calorie diet. Six studies compared dietary advice with dietary advice plus exercise and three other studies assessed dietary advice versus dietary advice plus behavioural approaches. The studies all measured weight and measures of glycaemic control although not all studies reported these in the articles published. Other outcomes which were measured in these studies included mortality, blood pressure, serum cholesterol (including LDL and HDL cholesterol), serum triglycerides, maximal exercise capacity and compliance. The results suggest that adoption of regular exercise is a good way to promote better glycaemic control in type 2 diabetic patients, however all of these studies were at high risk of bias.

AUTHORS' CONCLUSIONS

There are no high quality data on the efficacy of the dietary treatment of type 2 diabetes, however the data available indicate that the adoption of exercise appears to improve glycated haemoglobin at six and twelve months in people with type 2 diabetes. There is an urgent need for well-designed studies which examine a range of interventions, at various points during follow-up, although there is a promising study currently underway.

Leptin predicts the development of diabetes in Mauritian men, but not women: a population–based study

OBJECTIVE

To determine if levels of the adipocyte-derived hormone, leptin, predict the development of type 2 diabetes.

METHODS

Population-based surveys were undertaken in the multiethnic nation of Mauritius in 1987, 1992 and 1998. Questionnaires, anthropometric measurements, and a 2-h 75-g oral glucose tolerance test were included. A cohort of 2330 participants who were free of diabetes, aged 25-79 years in 1987, and who were followed-up in 1992 and 1998 was studied. Serum leptin was measured in baseline samples. Glucose tolerance was classified according to WHO (World Health Organization) 1999 criteria.

RESULTS

In total, 456 subjects developed diabetes over 11 years with similar incidences in all ethnic groups (P=0.2). Baseline leptin correlated positively with anthropometric measurements, fasting and postload insulin and homeostasis model assessment indices (all P<0.001), and inversely with subsequent weight increase. Participants with incident diabetes had higher serum levels of leptin at baseline than those remaining nondiabetic (P<0.001). After adjustment for confounders, high leptin levels and high leptin/body mass index ratio were independently associated with incident diabetes over 11 years in men (odds ratio for top versus bottom quartile of leptin 2.18; 95% CI: 1.09-4.35), but not in women.

CONCLUSION

We conclude that high leptin levels are associated with the future development of diabetes, and the association is independent of other factors in men, but not in women.

Mesenteric fat thickness as an independent determinant of fatty liver

OBJECTIVE

Mesenteric fat is drained by the portal circulation and has been suggested to be a key component in obesity-related health risk, notably the metabolic syndrome. There are increasing epidemiological and experimental data showing that fatty liver is another component of this multifaceted syndrome. Given their intimate anatomical and physiological relationships, we hypothesized that mesenteric fat thickness may be independently associated with the risk of fatty liver. To test this hypothesis, we examined the predictive role of various fat deposits including mesenteric fat thickness, and various metabolic variables on the risk of fatty liver.

SUBJECTS AND METHODS

A total of 291 Chinese subjects (134 men and 157 women with a mean BMI of 23.7 kg/m2, range: 16.5-33.4 kg/m2) underwent ultrasound examination for measurement of mesenteric, subcutaneous and preperitoneal fat thickness, and for diagnosis of fatty liver. Body mass index, waist circumference, and waist-hip ratio were recorded. Blood pressure was measured. Fasting plasma glucose, insulin resistance, high-density lipoprotein cholesterol (HDL-C), triglycerides, low-density lipoprotein cholesterol (LDL-C), liver enzymes were determined by common methods.

RESULTS

The subjects with fatty liver had greater abdominal fat thickness and higher anthropometric indexes than those without fatty liver. The subjects with fatty liver also showed higher blood pressure, worse lipid and glycaemic profile compared with those without fatty liver. Using multiple logistic regression analysis, mesenteric fat thickness was a risk factor of fatty liver, independent of body mass index, age, sex, insulin resistance, fasting plasma glucose, lipid and blood pressure. The odds ratio was 1.5 (95% confidence interval: 1.27-1.77) for every 1 mm increase in the mesenteric fat thickness. Measurement of preperitoneal and subcutaneous fat deposits did not show significant associations with fatty liver.

CONCLUSION

Mesenteric fat thickness measured on ultrasound is an independent determinant of fatty liver.

How well do rapid-acting insulins work in obese individuals?

Diabetes has reached epidemic proportions worldwide and most individuals with type 2 diabetes are obese. Therefore, there is a pressing need to carefully evaluate the impact of obesity on the efficacy of all diabetes therapies. Previously, obesity has been shown to adversely affect the efficacy of oral antidiabetic drugs; however, less is known about the impact of obesity on the properties of insulin and its analogues. As patients near target HbA1c, the more postprandial hyperglycaemia contributes to overall glycaemic control; thus, mealtime insulin, often supplied by a rapid-acting insulin analogue (RAI), becomes of increasing importance. As glycaemic targets set by professional bodies become lower and poor glycaemic control becomes increasingly less acceptable, earlier addition of RAIs to patients' treatment regimens may be required to meet these targets. However, in clinical practice, multiple barriers have challenged the acceptance and effective use of insulin therapy, including concern that it may cause weight gain. RAIs should ideally maintain their rapid-acting pharmacokinetic (PK) and pharmacodynamic (PD) profiles, irrespective of subcutaneous body fat, skin thickness and body mass index, in order to effectively meet intensive treatment goals. For example, initial PK/PD data with insulin glulisine in obese individuals suggest that this RAI may maintain its rapid-acting profile better than insulin lispro in the first 2 hours post-injection. However, data are preliminary and a thorough analysis of the impact of obesity on all RAIs in type 2 diabetes is warranted. This review focuses on the potential impact of obesity on RAIs and presents an overview of investigations in this area.

Changing Our Future

Obesity, or overweight, in childhood is a major risk factor for the metabolic syndrome in adolescence, as the prevalence in US children tripled between 1970 and 2000. An increase in the metabolic syndrome in youth has followed this increase. In population-based studies, the prevalence of the syndrome ranged from 3.6% to 4.2%. In smaller studies with many overweight youth, the prevalence was 28.7% to 39.7% in those who were overweight and 49.7% in those who were severely obese. Overweight children are likely to have hyperinsulinemia, high-density lipoprotein cholesterol, high triglycerides, and hypertension, which are components of the metabolic syndrome. Nurses have an important role in screening for these metabolic syndrome components. Screening is especially important in boys and girls who are overweight and in girls with early menarche. A problem when screening children and adolescents is determining normative values, but guidelines are available. Prevention and management of the metabolic syndrome are not specific to the syndrome, but rather should be focused on the underlying problem of overweight and related problems that comprise the syndrome. We must use all avenues available to us, including influencing public and school policies, and pay close attention to overweight and metabolic syndrome components in our clinical practice, whether with children or adults. Preventing and managing the metabolic syndrome should be a family matter, and the necessary lifestyle changes will benefit the entire family.

Insulin resistance and impaired glucose metabolism in a predominantly Maori community

We sought to identify lifestyle behaviours which influence risk of impaired glucose metabolism, IGM (newly diagnosed type 2 diabetes, impaired glucose tolerance [IGT] or impaired fasting glycemia [IFG]) or insulin resistance (IR) in a predominantly Maori community, and applied the McAuley formula to determine whether it predicts high risk individuals amongst this community. Three hundred and seventy one participants completed a lifestyle and dietary behaviour questionnaire and oral glucose tolerance test. Clinical variables, microalbuminuria, fasting glucose, insulin and lipids were measured. Diabetes, IFG and IGT were defined according to WHO criteria. IR was defined using the McAuley formula. Those with IGM and those with IR showed similar risk factor attributes. Odds ratios (95% CI) for development of IGM and IR were 0.43 (0.21-0.88) and 0.51 (0.33-0.80), respectively, for regular physical activity, and 0.55 (0.26-1.15) and 0.59 (0.37-0.96), respectively, for two or more dietary behaviours characterized by a high intake of fibre. Regular physical activity and a diet characterized by a high intake of dietary fibre were found to reduce risk of newly diagnosed IGM or IR. The McAuley formula appears to predict high-risk individuals in a predominantly Maori population as it does in European populations.

Prevalence of Type 2 diabetes and central adiposity in La Reunion Island, the REDIA Study

La Reunion Island, a French overseas department in the Indian Ocean provides an example of rapid urbanisation and drastic changes in the way of life--from traditional to "westernized" lifestyle--over a few decades. To study the impact of this epidemiologic transition, a diabetes prevalence study was performed in 1999-2001. Fasting capillary blood glucose (cBG) and glycated hemoglobin (HbA1c) were systematically measured in a random sample of 3600 subjects aged 30-69 years. Weight, height, waist and hip circumferences were also measured to assess body mass index and waist-hip ratio. Diagnosis was assessed using an oral glucose tolerance test according to the World Health Organization recommendations in 363 subjects who had a cBG value > or =6.1 mmol/l, and/or a HbA1c value > or =6%. The overall diabetes prevalence rate was 17.7% for men and 17.3% for women, and the standardized diabetes prevalence rate was 20.1% (95% confidence interval: 18.7-21.4%). The most important morphological factor linked to Type 2 diabetes mellitus was waist-hip ratio, a marker of central adiposity, especially in women. This study confirms that Type 2 diabetes is increasing dramatically in societies in epidemiologic transition and is strongly linked to nutritional status.

Prevention of type 2 diabetes by lifestyle intervention: a Japanese trial in IGT males

Prevention of type 2 diabetes by intensive lifestyle intervention designed to achieve and maintain ideal body weight was assessed in subjects with impaired glucose tolerance (IGT). Male subjects with IGT recruited from health-screening examinees were randomly assigned in a 4:1 ratio to a standard intervention group (control group) and intensive intervention group (intervention group). The final numbers of subjects were 356 and 102, respectively. The subjects in the control group and in the intervention group were advised to maintain body mass index (BMI) of <24.0 kg/m2 and of <22.0 kg/m2, respectively, by diet and exercise. In the intervention group, detailed instructions on lifestyle were repeated every 3-4 months during hospital visits. Diabetes was judged to have developed when two or more consecutive fasting plasma glucose (FPG) values exceeded 140 mg/dl. A 100g oral glucose tolerance test was performed every 6 months to detect improvement of glucose tolerance. The subjects were seen in an ordinary outpatient clinic. The cumulative 4-year incidence of diabetes was 9.3% in the control group, versus 3.0% in the intervention group, and the reduction in risk of diabetes was 67.4% (P < 0.001). Body weight decreased by 0.39 kg in the control group and by 2.18 kg in the intervention group (P < 0.001). The control group was subclassified according to increase and decrease in body weight. The incidence of diabetes was positively correlated with the changes in body weight, and the improvement in glucose tolerance was negatively correlated. Subjects with higher FPG at baseline developed diabetes at a higher rate than those with lower FPG. Higher 2h plasma glucose values and higher BMI values at baseline were also associated with a higher incidence of diabetes, but the differences were not significant. Subjects with a low insulinogenic index (DeltaIRI/DeltaPG 30 min after an oral glucose load) developed diabetes at a significantly higher rate than those with a normal insulinogenic index. Comparison of the BMI data and incidence of diabetes in five diabetes prevention studies by lifestyle intervention revealed a linear correlation between the incidence of diabetes and the BMI values, with the exception of the DaQing Study. However, the slope of the reduction in incidence of diabetes in the intensive intervention groups was steeper than expected simply on the basis of the reduction of BMI, suggesting that the effect of lifestyle intervention cannot be solely ascribed to the body weight reduction. We conclude that lifestyle intervention aimed at achieving ideal body weight in men with IGT is effective and can be conducted in an outpatient clinic setting.

Increasing prevalence of Type 2 diabetes mellitus in all ethnic groups in Mauritius

AIMS

To describe the prevalence of different stages of glucose intolerance in a population from Mauritius followed over 11 years.

METHODS

Population-based surveys were undertaken in the multiethnic nation of Mauritius in 1987, 1992 and 1998, with 5083, 6616, and 6291 participants, respectively. Questionnaires, anthropometric measurements, and a 2-h 75-g oral glucose tolerance test were included. Subjects aged between 25 and 75 years with classifiable data were identified; 4991, 6463 and 5392 from 1987, 1992 and 1998, respectively. Glucose tolerance was classified according to WHO 1999 criteria.

RESULTS

The prevalence of Type 2 diabetes increased significantly during the period studied, from 12.8% in 1987, to 15.2% in 1992, and 17.9% in 1998. The increasing prevalence was seen in both men and women, and in all age groups. The prevalence of known diabetes (KDM) increased progressively, and more markedly than the increase in newly diagnosed diabetes (NDM). A diagnosis of impaired glucose tolerance (IGT) was more prevalent amongst women whereas impaired fasting glucose (IFG) was more common amongst men. The prevalences of IGT and IFG did not change markedly during the period. The prevalence of diabetes and IGT was similar for participants of Indian, Creole and Chinese background in each survey, and the increasing prevalence of diabetes was seen in all ethnic groups.

CONCLUSION

In this study, we report an increasing prevalence of diabetes over an 11-year period in Mauritius. This increase was seen in both sexes, and in all age and ethnic groups, and was mainly due to an increase in the numbers of those with known diabetes.

Physical activity and television viewing in relation to risk of undiagnosed abnormal glucose metabolism in adults

OBJECTIVE

The goal of this study was to assess the associations of physical activity time and television (TV) time with risk of "undiagnosed" abnormal glucose metabolism in Australian adults.

RESEARCH DESIGN AND METHODS

This population-based cross-sectional study using a stratified cluster design involving 42 randomly selected Census Collector Districts across Australia included 8,299 adults aged 25 years or older who were free from new type 2 diabetes and self-reported ischemic disease and did not take lipid-lowering or antihypertensive drugs. Abnormal glucose metabolism (impaired fasting glycemia [IFG], impaired glucose tolerance [IGT], or new type 2 diabetes) was based on an oral glucose tolerance test. Self-reported physical activity time and TV time (previous week) were assessed using interviewer-administered questionnaires.

RESULTS

After adjustment for known confounders and TV time, the odds ratio (OR) of having abnormal glucose metabolism was 0.62 (95% CI 0.41-0.96) in men and 0.71 (0.50-1.00) in women for those engaged in physical activity >or=2.5 h/week compared with those who were sedentary (0 h/week). The ORs of having abnormal glucose metabolism were 1.16 (0.79-1.70) in men and 1.49 (1.12-1.99) in women who watched TV >14 h/week compared with those who watched <or=7.0 h/week. Higher TV viewing (>14 h/week) was also associated with an increased risk of new type 2 diabetes in men and women and IGT in women compared with those watching <14 h/week. Total physical activity of >or=2.5 h/week was associated with a reduced risk of IFG, IGT, and new type 2 diabetes in both sexes; however, only the association with IGT in women was statistically significant.

CONCLUSIONS

These findings suggest a protective effect of physical activity and a deleterious effect of TV time on the risk of abnormal glucose metabolism in adults. Population strategies to reduce risk of abnormal glucose metabolism should focus on reducing sedentary behaviors such as TV time, as well as increasing physical activity.

The epidemiology of central fat distribution in relation to disease

The effect of fat distribution on disease risk is a subject of great interest. Central fat has been measured anthropometrically, by computed tomography, and by magnetic resonance imaging. Both cross-sectional and longitudinal studies have related central fat to type 2 diabetes mellitus and cardiovascular disease, independent of body mass index. The mechanism may relate to increased lipolysis causing the liver to increase glucose and very low density lipoprotein output, while muscle uses less. This leads to a rise in blood glucose and triglycerides, a drop in HDL cholesterol, and an increase in small, dense LDL particles. There is also an increase in blood pressure and inflammatory markers. Certain populations put on excess fat more centrally than others. These include Asian populations. It is likely that with better differentiation of abdominal fat into visceral and subcutaneous depots, clearer data will accrue on their impact on disease risk.

High incidence of type 2 diabetes and increasing conversion rates from impaired fasting glucose and impaired glucose tolerance to diabetes in Mauritius

OBJECTIVE

To describe the incidence of different stages of glucose intolerance in a population from Mauritius followed over 11 years. RESEARCH DESIGN, METHODS AND SUBJECTS: Population-based surveys were undertaken in the multi-ethnic nation of Mauritius in 1987, 1992 and 1998 with 5083, 6616 and 6291 participants, respectively. Questionnaires, anthropometric measurements, and a 2-h 75-g oral glucose tolerance test were included. Three cohorts aged between 25 and 79 years with classifiable glucose tolerance data were identified; 3680 between 1987 and 1992, 4178 between 1992 and 1998, and 2631 between 1987 and 1998. Glucose tolerance was classified according to WHO 1999 criteria.

RESULTS

The incidence rate of type 2 diabetes was higher between 1992 and 1998 than between 1987 and 1992. In men, the incidence was similar between cohorts (24.5 and 25.4 per 1000 person-years) whereas the incidence increased in women (23.3 and 16.4 per 1000 person-years). The incidence of diabetes peaked in the 45-54 year age group and then plateaued or fell. The incidences of impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) decreased in both men and women. Of normoglycaemic subjects at baseline, more women than men developed IGT and more men than women developed IFG. Of those labelled as IFG in 1987, 38% developed diabetes after 11 years. The corresponding figure for IGT was 46%.

CONCLUSIONS

In this study, we report changes in incidence rates of glucose intolerance over a 11-year period. In particular, differences between men and women were observed. The increased incidence of IGT in women compared with men, and increased incidence of IFG in men compared with women was consistent with, and explains the sex biases seen in the prevalences of these states.

Diabetes-related inequalities in health status and financial barriers to health care access in a population-based study

AIMS

We evaluated the relationship between diabetes, health status, household income and expenditure on health care in the general population in Trinidad.

METHODS

Multistage sampling of 300 households was used to select a sample of 548 adults aged > or = 25 years. There were 64 (12%) who reported a diagnosis of diabetes. Comparison was made with 128 non-diabetic controls who were frequency matched for age and sex.

RESULTS

Subjects with diabetes had lower income levels than non-diabetic controls [income < or = US dollars 533 per month for 66% diabetes cases and 48% controls, test for trend P = 0.007]. Compared with controls, subjects with diabetes were less likely to have good or very good self-rated health (diabetes 32%, controls 67%; P < 0.001), and more frequently reported long-standing illness, limitation of activities, visual impairment, or self-reported history of high blood pressure, angina or heart attack. Subjects with diabetes (11%) were less likely than controls (30%) to have private health insurance (P = 0.005). Diabetic subjects (35%) were more likely than controls (16%) to have incurred expenditure on doctors' services in the last 4 weeks (P = 0.021).

CONCLUSIONS

Diabetes is associated with worse health status and more frequent expenditure on medical services but greater financial barriers to access in terms of low income and lack of health insurance. Policies for diabetes should specifically address the problem of income-related variations in risk of diabetes, health care needs and barriers to uptake of preventive and treatment services, otherwise inequalities in health from this condition may increase.

Sonographic measurement of mesenteric fat thickness is a good correlate with cardiovascular risk factors: comparison with subcutaneous and preperitoneal fat thickness, magnetic resonance imaging and anthropometric indexes

OBJECTIVE

Visceral fat, notably mesenteric fat, which is drained by the portal circulation, plays a critical role in the pathogenesis of metabolic syndrome through increased production of free fatty acids, cytokines and vasoactive peptides. We hypothesize that mesenteric fat thickness as measured by ultrasound scan could explain most of the obesity-related health risk. We explored the relationships between cardiovascular risk factors and abdominal fat as determined by sonographic measurements of thickness of mesenteric, preperitoneal and subcutaneous fat deposits, total abdominal and visceral fat measurement by magnetic resonance imaging (MRI) and anthropometric indexes.

DESIGN

A cross-sectional study.

SUBJECTS

Subjects included 18 healthy men and 19 women (age: 27-61 y, BMI: 19-33.4 kg/m(2)).

MEASUREMENTS

The maximum thickness of mesenteric, preperitoneal and subcutaneous fat was measured by abdominal ultrasound examination. MRI examinations of whole abdomen and pelvis were performed and the amount of total abdominal and visceral fat was quantified. The body mass index, waist circumference and waist-hip ratio were recorded. Cardiovascular risk factors were assessed by physical examination and blood taking.

RESULTS

Men had more adverse cardiovascular risk profile, higher visceral fat volume and thicker mesenteric fat deposits than women. Among all the investigated obesity indexes, the mesenteric fat thickness showed the highest correlations with total cholesterol, LDL-C, triglycerides, fasting plasma glucose, HbA(1c) and systolic blood pressure in men, and with triglycerides and HbA(1c) in women. On stepwise multiple regression analysis with different obesity indexes as independent variables, 30-65% of the variances of triglycerides, total cholesterol, LDL-C and HbA(1c) in men, and triglycerides in women were explained by the mesenteric fat thickness.

CONCLUSION

Compared with sonographic measurement of subcutaneous and preperitoneal fat thickness, MRI measurement of total abdominal and visceral fat and anthropometric indexes, sonographic measurement of mesenteric fat thickness showed better associations with some of the cardiovascular risk factors. It may potentially be a useful tool to evaluate regional distribution of obesity in the assessment of cardiovascular risk.

Clinical and pathophysiological consequences of abdominal adiposity and abdominal adipose tissue depots

OBJECTIVES

To highlight the clinical and metabolic correlates of abdominal obesity and various abdominal adipose tissue depots.

METHODS

We researched the topic using the search terms abdominal obesity, central obesity, visceral obesity, regional obesity, and subcutaneous adipose tissue from MEDLINE (National Library of Medicine, Bethesda, MD), PubMed (National Library of Medicine, Bethesda, MD), Current Contents (Institute for Scientific Information, Thomson Scientific, Philadelphia, PA), and using manual search for the cited references.

RESULTS

Abdominal obesity contributes significantly to the metabolic perturbations and cardiovascular risk in human beings. Abdominal adipose tissue depots (intraabdominal and subcutaneous [deep subcutaneous, posterior subcutaneous]) are metabolically active and appear to be important for the pathogenesis of insulin resistance, dyslipidemia, glucose intolerance, hypertension, hypercoagulable state, and cardiovascular risk. Adipocyte anatomy (size), physiology (growth, catecholamine sensitivity, lipolysis, insulin action), and biochemistry (leptin, plasminogen activator inhibitor-1, cytokines, renin-angiotensin system) are reported to be relatively site-specific, highlighting unique roles of regional adipose tissue depots.

CONCLUSIONS

Several physiological and metabolic parameters are site-specific in abdominal adipose tissue. The epidemiological, clinical, and prognostic significance and relative importance of the regional adipose tissue depots, however, remain to be ascertained.

Visceral adiposity and the risk of impaired glucose tolerance: a prospective study among Japanese Americans

OBJECTIVE

Greater visceral adiposity, higher insulin resistance, and impaired insulin secretion increase the risk of type 2 diabetes. Whether visceral adiposity increases risk of impaired glucose tolerance (IGT) independent of other adipose depots, insulin resistance, and insulin secretion is not known.

RESEARCH DESIGN AND METHODS

Study subjects included 128 Japanese Americans with normal glucose tolerance at entry. Baseline variables included plasma glucose and insulin measured after an overnight fast and during a 75-g oral glucose tolerance test, fat areas by computed tomography, insulin secretion (incremental insulin response [IIR] [30 min insulin - fasting insulin]/30 min glucose), and insulin resistance index (homeostasis model assessment for insulin resistance [HOMA-IR]).

RESULTS

During the 10- to 11-year follow-up period, we confirmed 57 cases of IGT. Significant predictors of IGT included intra-abdominal fat area (IAFA) (odds ratio [OR] for a 1 SD increase 3.82, 95% CI 1.63-8.94 at a fasting plasma glucose [FPG] level of 4.5 mmol/l), HOMA-IR (2.41, 1.15-5.04), IIR (0.30, 0.13-0.69 at an FPG level of 4.5 mmol/l), the interactions of IAFA by FPG (P = 0.003), and IIR by FPG (P = 0.030) after adjusting for age, sex, FPG, and BMI. The multiple-adjusted OR of IAFA increased and that of IIR decreased as FPG level decreased because of these interactions. Even after adjustment for total fat area, total subcutaneous fat area, or abdominal subcutaneous fat area, all of these associations remained a significant predictor of IGT incidence.

CONCLUSIONS

Greater visceral adiposity increases the risk of IGT independent of insulin resistance, insulin secretion, and other adipose depots in Japanese Americans.

Prevention of type 2 diabetes in young people: a theoretical perspective

Type 2 diabetes in youth is an increasing public health concern, especially in certain minority populations. The current paper consists of four sections. First, we establish the significance of the problem by presenting an overview of epidemiological and physiological evidence. Second, we discuss behavioral issues relevant to the prevention of type 2 diabetes in youth. Third, a qualitative review of existing prevention interventions specific to type 2 diabetes in youth is presented. Results suggest that modest improvements in social cognitive, dietary, and exercise outcomes are possible with diabetes intervention studies, although beneficial changes are difficult to sustain over the long term. Although theoretical frameworks are not always explicit, most studies have utilized elements of the social cognitive theory. Less attention has been paid to sociocultural and community organization variables. Finally, the paper discusses issues of risk definition and intervention sustainability, and presents a comprehensive, theoretically diverse model for the prevention of type 2 diabetes in youth. In summary, we suggest that theories of the natural history and pathophysiology of type 2 diabetes are important to identify modifiable risk factors, while theories of behavioral change are essential to modify the risk factors identified. The combination of sound physiological and behavioral theories should form the basis of prevention intervention design. In addition, an ecologic approach that takes into consideration the dynamic interactions of personal, social, and environmental factors would best promote the long-term adoption of healthful behaviors in a supportive, meaningful, and personally enjoyable context.

Dietary patterns and risk factors for type 2 diabetes mellitus in Fijian, Japanese and Vietnamese populations

Diabetes mellitus is now a serious and increasing problem in Asian countries, where dietary patterns have shifted toward Westernized foods and people are becoming more sedentary. In order to elucidate the relationship of dietary habits to the development of diabetic risk factors, the dietary patterns of 200 Fijian, 171 Japanese and 181 Vietnamese women of 30-39 years of age were investigated using 3 day-24 h recall or dietary records. Anthropometric measurements and glycosuria tests were also conducted. The dietary trends of Fijians and Japanese have changed drastically in the past 50 years, while Vietnamese have been minimally influenced by Western dietary habits. The mean 24 h dietary intake showed that Fijians had the highest energy intake. Energy intake from fat was only 13% for Vietnamese, but over 30% for Japanese and Fijians. Percentage of body fat was higher in Vietnamese than in Japanese, though there were no significant differences in body mass index (BMI). In the overweight and obese women, Vietnamese had higher abdominal obesity than Japanese. The prevalence of obesity (BMI > or = 30 kg/m2) was 63.0% for Fijians, 1.8% for Japanese and 1.1% for Vietnamese. Glycosuria testing yielded the most positive cases among Fijians. Dietary transition and dietary excess appear to be potential risk factors for diabetes in Fijian women.