Epidemiology of diabetes.

The disease burden related to diabetes is high and rising in every country, fuelled by the global rise in the prevalence of obesity and unhealthy lifestyles. The latest estimates show a global prevalence of 382 million people with diabetes in 2013, expected to rise to 592 million by 2035. The aetiological classification of diabetes has now been widely accepted. Type 1 and type 2 diabetes are the two main types, with type 2 diabetes accounting for the majority (>85%) of total diabetes prevalence. Both forms of diabetes can lead to multisystem complications of microvascular endpoints, including retinopathy, nephropathy and neuropathy, and macrovascular endpoints including ischaemic heart disease, stroke and peripheral vascular disease. The premature morbidity, mortality, reduced life expectancy and financial and other costs of diabetes make it an important public health condition.NGF and NJW acknowledge support from the core Medical Research Council Epidemiology Unit Programmes ( MC_UU_12015/5 and MC_UU_12015/1 ).This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.mpmed.2014.09.00

The EPIC-InterAct Study: A Study of the Interplay between Genetic and Lifestyle Behavioral Factors on the Risk of Type 2 Diabetes in European Populations.

The rising prevalence of type 2 diabetes around the world and the global pattern of variation in risk between countries have been widely attributed to an interplay between rising rates of obesity and poor lifestyles, and genetic or developmental susceptibility to disease. Although this general hypothesis has been in existence for more than 50 years, the precise mechanisms that may explain it have remained uncertain. Advances in technology and the application of new methods in large scale population studies have made it possible to study these mechanisms. The InterAct project, funded by the European Commission, is a large case-cohort study which has verified 12,403 incident cases of type 2 diabetes, facilitating the study of genetic and lifestyle factors on the risk of type 2 diabetes among European populations.This is the final version. It was first published by Springer in Current Nutrition Reports at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4218968

Validity and repeatability of a simple index derived from the short physical activity questionnaire used in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

Original article can be found at: http://journals.cambridge.org/action/displayJournal?jid=PHN Copyright The Authors. DOI: 10.1079/PHN2002439Peer reviewe

Estimation of Physical Activity Energy Expenditure during Free-Living from Wrist Accelerometry in UK Adults.

BACKGROUND: Wrist-worn accelerometers are emerging as the most common instrument for measuring physical activity in large-scale epidemiological studies, though little is known about the relationship between wrist acceleration and physical activity energy expenditure (PAEE). METHODS: 1695 UK adults wore two devices simultaneously for six days; a combined sensor and a wrist accelerometer. The combined sensor measured heart rate and trunk acceleration, which was combined with a treadmill test to yield a signal of individually-calibrated PAEE. Multi-level regression models were used to characterise the relationship between the two time-series, and their estimations were evaluated in an independent holdout sample. Finally, the relationship between PAEE and BMI was described separately for each source of PAEE estimate (wrist acceleration models and combined-sensing). RESULTS: Wrist acceleration explained 44-47% between-individual variance in PAEE, with RMSE between 34-39 J•min-1•kg-1. Estimations agreed well with PAEE in cross-validation (mean bias [95% limits of agreement]: 0.07 [-70.6:70.7]) but overestimated in women by 3% and underestimated in men by 4%. Estimation error was inversely related to age (-2.3 J•min-1•kg-1 per 10y) and BMI (-0.3 J•min-1•kg-1 per kg/m2). Associations with BMI were similar for all PAEE estimates (approximately -0.08 kg/m2 per J•min-1•kg-1). CONCLUSIONS: A strong relationship exists between wrist acceleration and PAEE in free-living adults, such that irrespective of the objective method of PAEE assessment, a strong inverse association between PAEE and BMI was observed

Accordance to the Dietary Approaches to Stop Hypertension diet pattern and cardiovascular disease in a British, population-based cohort.

The dietary approaches to stop hypertension (DASH) diet could be an important population-level strategy to reduce cardiovascular disease (CVD) in the UK, but there is little UK-based evidence on this diet pattern in relation to CVD risk. We tested whether dietary accordance with DASH was associated with risk of CVD in a population-based sample of 23,655 UK adults. This prospective analysis of the EPIC-Norfolk cohort study analysed dietary intake (assessed using a validated food frequency questionnaire) to measure accordance with DASH, based on intakes of eight food groups and nutrients, ranking the sample into quintiles. Cox proportional hazards regression models tested for association between DASH accordance and incident stroke, ischemic heart disease (IHD) and total incident CVD (stroke and IHD only), as well as CVD mortality, non-CVD mortality and total mortality. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated adjusting for age, sex, behavioral and clinical risk factors and socioeconomic status. Over an average of 12.4 years follow-up, we ascertained 4129 incident CVD events, of which stroke accounted for 1011. Compared to participants with the least DASH-accordant diets, those with the most DASH-accordant diets had 20% lower risk of incident stroke (HR, 95% CI 0.80, 0.65-0.99) and 13% lower risk of total incident CVD (0.88, 0.79-0.99) but no lower risk of CHD (0.90, 0.79-1.02). CVD-related mortality also showed strong inverse associations with DASH accordance (0.72, 0.60-0.85). This study provides evidence for the cardioprotective effects of DASH diet in a UK context

The cross-sectional association between snacking behaviour and measures of adiposity: the Fenland Study, UK.

Unhealthy dietary behaviours may contribute to obesity along with energy imbalance. Both positive and null associations of snacking and BMI have been reported, but the association between snacking and total adiposity or pattern of fat deposition remains unevaluated. The objective of this study was to investigate the associations between snacking frequency and detailed adiposity measurements. A total of 10 092 adults residing in Cambridgeshire, England, self-completed eating pattern snacking frequency, FFQ and physical activity questionnaires. Measurements included anthropometry, body composition using dual-energy X-ray absorptiometry scan and ultrasound and assessment of physical activity energy expenditure using heart rate and movement sensing. Linear regression analyses were conducted adjusted for age, socio-demographics, dietary quality, energy intake, PAEE and screen time by sex and BMI status. Among normal-weight individuals (BMI<25 kg/m2), each additional snack was inversely associated with obesity measures: lower total body fat in men and women (-0·41 (95 % CI -0·74, -0·07) %, -0·41 (-0·67, -0·15) %, respectively) and waist circumference (-0·52 (-0·90, -0·14) cm) in men. In contrast, among the overweight/obese (BMI≥25 kg/m2), there were positive associations: higher waist circumference (0·80 (0·34, 0·28) cm) and subcutaneous fat (0·06 (0·01, 0·110) cm) in women and waist circumference (0·37 (0·00, 0·73) cm) in men. Comparing intakes of snack-type foods showed that participants with BMI≥25 kg/m2 had higher intakes of crisps, sweets, chocolates and ice-creams and lower intakes of yoghurt and nuts compared with normal-weight participants. Adjusting for these foods in a model that included a BMI-snacking interaction term attenuated all the associations to null. Snacking frequency may be associated with higher or lower adiposity, with the direction of association being differential by BMI status and dependent on snack food choice. Improving snack choices could contribute to anti-obesity public health interventions.The Fenland Study is funded by the Wellcome Trust and the Medical Research Council. Support from Medical Research Council programmes MC_UU_12015/1 and MC_UU_12015/5 is acknowledged.This is the final version of the article. It first appeared from British Journal of Nutrition via http://dx.doi.org/10.1017/S000711451500269

Longitudinal association of C-reactive protein and Haemoglobin A1c over 13 years: the European Prospective Investigation into Cancer - Norfolk study

Abstract Background Type-2 diabetes is associated with systemic inflammation and higher C-reactive protein (CRP) levels. However, the longitudinal association of CRP and haemoglobin-A1c (HbA1c) has not been described in large prospective studies. Understanding such associations may shed light on the role of inflammation in development of type-2 diabetes and its complications such as cardiovascular diseases. Methods EPIC-Norfolk is a cohort study of men and women aged 40–79 years at time of recruitment (1993–1997). Serum CRP (mg/l) was measured using a high-sensitivity assay at baseline and 13-years follow-up. HbA1c (%) was measured at baseline, 4, and 13 years. Participants were excluded if they were diagnosed with diabetes or were taking diabetes medication. Data on at least one measurement of CRP and HbA1c was available for 14228 participants (55 % of the cohort). Results In the cross-sectional analysis of baseline data, a 1-SD higher loge-CRP (about three-fold higher CRP) was associated with 0.06 (95 % CI 0.04, 0.08) higher HbA1c (%) adjusted for potential confounders. In longitudinal analysis using multivariable linear mixed models, change in CRP over 13 years was to a similar extent positively associated with increase in HbA1c, such that 1-SD higher longitudinal change in loge-CRP was associated with 0.04 (95 % CI 0.02, 0.05) increase in HbA1c. Conclusion In this study we found longitudinal observational evidence suggesting that increase in systemic inflammation is associated with an increase in HbA1c and thus systemic inflammation may have a role in development of type-2 diabetes and its complications

Dietary dairy product intake and incident type 2 diabetes: a prospective study using dietary data from a 7-day food diary

The consumption of specific dairy types may be beneficial for the prevention of diabetes. Abstract: The aim of this study was to investigate the association between total and types of dairy product intake and risk of developing incident type 2 diabetes, using a food diary. Methods: A nested case-cohort within the EPIC-Norfolk Study was examined, including a random subcohort (n=4,000) and cases of incident diabetes (n=892, including 143 cases in the subcohort) followed-up for 11 years. Diet was assessed using a prospective 7-day food diary. Total dairy intake (g/day) was estimated and categorised into high-fat (≥3.9%) and low-fat (&lt;3.9% fat) dairy, and by subtype into yoghurt, cheese and milk. Combined fermented dairy product intake (yoghurt, cheese, sour cream) was estimated and categorised into high- and low-fat. Prentice-weighted Cox regression HRs were calculated. Results: Total dairy, high-fat dairy, milk, cheese and high-fat fermented dairy product intakes were not associated with the development of incident diabetes. Low-fat dairy intake was inversely associated with diabetes in age- and sex-adjusted analyses (tertile [T] 3 vs T1, HR 0.81 [95% CI 0.66, 0.98]), but further adjustment for anthropometric, dietary and diabetes risk factors attenuated this association. In addition, an inverse association was found between diabetes and low-fat fermented dairy product intake (T3 vs T1, HR 0.76 [95% CI 0.60, 0.99]; ptrend=0.049) and specifically with yoghurt intake (HR 0.72 [95% CI 0.55, 0.95]; ptrend=0.017) in multivariable adjusted analyses. Conclusions/interpretation: Greater low-fat fermented dairy product intake, largely driven by yoghurt intake, was associated with a decreased risk of type 2 diabetes development in prospective analyses. These findings suggest that the consumption of specific dairy types may be beneficial for the prevention of diabetes, highlighting the importance of food group subtypes for public health messages

Patterns and correlates of objectively measured free-living physical activity in adults in rural and urban Cameroon.

BACKGROUND: Urbanisation in sub-Saharan Africa is changing lifestyles and raising non-communicable disease burden. Understanding the underlying pattern of physical activity and its correlates may inform preventive interventions. We examined correlates of objectively-measured physical activity in rural and urban Cameroon. METHODS: Participants were 544 adults resident in rural (W-156, M-89) or urban (W-189, M-110) regions. Physical activity was measured using individually-calibrated combined heart rate and movement sensing over seven continuous days. Sociodemographic data were collected by self-report. Independent associations of sociodemographic correlates with physical activity energy expenditure (PAEE) or moderate-to-vigorous physical activity (MVPA) were analysed in multivariate regression models. RESULTS: Rural dwellers were significantly more active than their urban counterparts (PAEE: 58.0 vs 42.9 kJ/kg/day; MVPA: 107 vs 62 min/day; MVPA of 150 min/week in >10 min bouts: 62 vs 39%) and less sedentary (923 vs 1026 min/day); p<0.001. There was no significant seasonal difference (dry vs rainy) in activity in urban dwellers whereas in rural dwellers activity was higher during dry seasons compared to rainy seasons (p<0.001). Age, obesity and education showed significant inverse associations with activity. Urban dwellers who considered themselves adequately active were only as active as rural dwellers who thought they were not adequately active. CONCLUSIONS: This is the first study providing data on sociodemographic patterning of objectively-measured physical activity in rural and urban sub-Saharan Africa. Age, urban residence, obesity and higher educational level are important correlates of lower levels of physical activity. These suggest targets for public health interventions to improve physical activity in Cameroon.This research was supported by the Wellcome Trust (074786/Z/04/Z) and the Medical Research Council Epidemiology Unit (MC_UU_12015/3).This is the final published version. It first appeared at http://jech.bmj.com/content/early/2015/04/03/jech-2014-205154.long

Estimation of Free-Living Energy Expenditure by Heart Rate and Movement Sensing: A Doubly-Labelled Water Study.

BACKGROUND: Accurate assessment of energy expenditure (EE) is important for the study of energy balance and metabolic disorders. Combined heart rate (HR) and acceleration (ACC) sensing may increase precision of physical activity EE (PAEE) which is the most variable component of total EE (TEE). OBJECTIVE: To evaluate estimates of EE using ACC and HR data with or without individual calibration against doubly-labelled water (DLW) estimates of EE. DESIGN: 23 women and 23 men (22-55 yrs, 48-104 kg, 8-46%body fat) underwent 45-min resting EE (REE) measurement and completed a 20-min treadmill test, an 8-min step test, and a 3-min walk test for individual calibration. ACC and HR were monitored and TEE measured over 14 days using DLW. Diet-induced thermogenesis (DIT) was calculated from food-frequency questionnaire. PAEE (TEE ÷ REE ÷ DIT) and TEE were compared to estimates from ACC and HR using bias, root mean square error (RMSE), and correlation statistics. RESULTS: Mean(SD) measured PAEE and TEE were 66(25) kJ·day(-1)·kg(-1), and 12(2.6) MJ·day(-1), respectively. Estimated PAEE from ACC was 54(15) kJ·day(-1)·kg(-1) (p<0.001), with RMSE 24 kJ·day(-1)·kg(-1) and correlation r = 0.52. PAEE estimated from HR and ACC+HR with treadmill calibration were 67(42) and 69(25) kJ·day(-1)·kg(-1) (bias non-significant), with RMSE 34 and 20 kJ·day(-1)·kg(-1) and correlations r = 0.58 and r = 0.67, respectively. Similar results were obtained with step-calibrated and walk-calibrated models, whereas non-calibrated models were less precise (RMSE: 37 and 24 kJ·day(-1)·kg(-1), r = 0.40 and r = 0.55). TEE models also had high validity, with biases <5%, and correlations r = 0.71 (ACC), r = 0.66-0.76 (HR), and r = 0.76-0.83 (ACC+HR). CONCLUSIONS: Both accelerometry and heart rate may be used to estimate EE in adult European men and women, with improved precision if combined and if heart rate is individually calibrated.The study received financial support from Wellcome Trust, Unilever UK, and the Medical Research Council (MC_UU_12015/3).This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pone.013720