Genetic variants and the metabolic syndrome: a systematic review

Several candidate gene studies on the metabolic syndrome (MetS) have been conducted. However, for most single nucleotide polymorphisms (SNPs) no systematic review on their association with MetS exists. A systematic electronic literature search was conducted until the 2nd of June 2010, using HuGE Navigator. English language articles were selected. Only genes of which at least one SNP–MetS association was studied in an accumulative total population =4000 subjects were included. Meta-analyses were conducted on SNPs with three or more studies available in a generally healthy population. In total 88 studies on 25 genes were reviewed. Additionally, for nine SNPs in seven genes (GNB3, PPARG, TCF7L2, APOA5, APOC3, APOE, CETP) a meta-analysis was conducted. The minor allele of rs9939609 (FTO), rs7903146 (TCF7L2), C56G (APOA5), T1131C (APOA5), C482T (APOC3), C455T (APOC3) and 174G>C (IL6) were more prevalent in subjects with MetS, whereas the minor allele of Taq-1B (CETP) was less prevalent in subjects with the MetS. After having systematically reviewed the most studied SNP–MetS associations, we found evidence for an association with the MetS for eight SNPs, mostly located in genes involved in lipid metabolis

Fitting additive Poisson models

This paper describes how to fit an additive Poisson model using standard software. It is illustrated with SAS code, but can be similarly used for other software packages

Reproducibility and relative validity of dietary glycaemic index and glycaemic load assessed by the food-frequency questionnaire used in the Dutch cohorts of the European prospective investigation into Cancer and Nutrition

Limited information is available on the reproducibility and validity of dietary glycaemic index (GI) and glycaemic load (GL) estimated by habitual diet assessment methods such as FFQ, including the FFQ used in the Dutch cohorts of the European Prospective Investigation into Cancer and Nutrition study. To examine the reproducibility and relative validity of GI and GL, we used data from 121 Dutch men and women aged 23–72 years. They completed the FFQ three times at intervals of 6 months and twelve 24-h dietary recalls (24HDR) monthly during 1991–2. GI and GL were calculated using published values. Intra-class correlation coefficients of the three repeated FFQ were 0·78 for GI and 0·74 for GL. Pearson correlation coefficients between the first FFQ and the weighted average of the 24HDR were 0·63 for both GI and GL. Weighted ¿ values between the first FFQ and the average of the 24HDR (in quintiles) were 0·40 for GI and 0·41 for GL. Bland–Altman plots showed a proportional bias in GI (ß = 0·46), but not in GL (ß = 0·06). In conclusion, this FFQ can be used in epidemiological studies to investigate the relationship of GI and GL with disease risks, but the proportional bias should be taken into account when using this FFQ to assess the absolute GI values

Abdominal obesity and the prevalence of diabetes and intermediate hyperglycaemia in Chinese adults

Objective: To assess the association of indicators of general and abdominal obesity with the prevalence of type 2 diabetes (T2DM) and intermediate hyperglycaemia (IHG) in the Chinese population. Methods: We used data of 50 905 adults aged 18¿79 years in the 2002 China National Nutrition and Health Survey. Recommended Chinese cut-off values were used for BMI (24 kg/m2) and waist circumference (WC; 85 cm in men, 80 cm in women). Optimal cut-offs for waist:height ratio (WHtR) were determined from analyses of receiver-operating characteristic (ROC) curves. Results: The prevalence of T2DM and IHG was 2?6% and 1?9% respectively. ROC curve analyses indicated 0?5 as the optimal cut-off value for WHtR in both sexes. High BMI, WC and WHtR were all associated with the prevalence of glucose tolerance abnormalities, with the highest prevalence ratio (PR) for high WHtR (men: PR52?85, 95% CI 2?54, 3?21; women: PR53?10, 95% CI 2?74, 3?51). When combining BMI and WHtR, in men either a high BMI or a high WHtR alone was associated with increased risk. Among women, a high BMI without a concomitant high WHtR was not associated with increased glucose tolerance abnormalities risk, whereas a high WHtR was associated with risk irrespective of BMI. Conclusions: Among the Chinese adult population measures of central obesity are better predictors of glucose tolerance abnormalities prevalence than BMI. AWHtR cutoff point of 0?5 for both men and women can be considered as optimum for predicting (pre-) diabetes and may be a useful tool for screening and health education

Association of metabolic syndrome with obesity measures, metabolic profiles, and intake of dietary fatty acids in people of Asian Indian origin

Objective: The present community-based cross-sectional study was aimed to examine the association of metabolic syndrome (MS) with obesity measures, metabolic profi les, and intake of dietary fatty acids in Asian Indian population. Patients and Methods: A total of 350 adult (30 years and above) individuals (184 males and 166 females) inhabiting in and around Kolkata, India participated in this study. MS was defi ned using the protocol specifi cally designed for Asian Indian population. Results: The prevalence of MS in the study was 31.4%. The prevalence was signifi cantly higher (P < 0.01) in females (48.2%) as compared to males (16.3%). It was observed that males without MS had signifi cantly higher mean waist circumference (WC P < 0.05); waist– hip ratio (WHR; P < 0.001); triglyceride (TG; P < 0.05); very low density lipoprotein cholesterol (VLDLc; P < 0.05) and fasting blood glucose (FBG; P < 0.01) as compared to females without MS. Signifi cant differences were also observed for dietary intake of total fatty acids (TFA; P < 0.001); saturated fatty acids (SFA; P < 0.001) and polyunsaturated fatty acids (PUFA; P < 0.001) between individuals with and without MS. However, no signifi cant association was observed in individuals with MS after controlling for age and sex. On the other, WC and body mass index (BMI) had signifi cant correlation with SFA: mono unsaturated fatty acids (MUFA; P < 0.01) in individuals without MS even after controlling for age and sex. Conclusion: It seem reasonabl

Validity of a short questionnaire to assess physical activity in 10 European countries

To accurately examine associations of physical activity (PA) with disease outcomes, a valid method of assessing free-living activity is required. We examined the validity of a brief PA questionnaire (PAQ) used in the European Prospective Investigation into Cancer and Nutrition (EPIC). PA energy expenditure (PAEE) and time spent in moderate and vigorous physical activity (MVPA) was measured in 1,941 healthy individuals from 10 European countries using individually-calibrated combined heart-rate and movement sensing. Participants also completed the short EPIC-PAQ, which refers to past year’s activity. Pearson (r) and Spearman (s) correlation coefficients were calculated for each country, and random effects meta-analysis was used to calculate the combined correlation across countries to estimate the validity of two previously- and one newly-derived ordered, categorical PA indices (“Cambridge index”, “total PA index”, and “recreational index”) that categorized individuals as inactive, moderately inactive, moderately active, or active. The strongest associations with PAEE and MVPA were observed for the Cambridge index (r = 0.33 and r = 0.25, respectively). No significant heterogeneity by country was observed for this index (I2 = 36.3%, P = 0.12; I2 = 0.0%, P = 0.85), whereas heterogeneity was suggested for other indices (I2 > 48%, P 47%, P <0.05). PAEE increased linearly across self-reported PA categories (P for tren

A meta-analysis of the effect of peer feedback on academic achievement in the STEM fields of higher education

Recently, there has been a significant increase in the use of peer feedback in higher education. However, the evidence of the effect of peer feedback on students’ academic achievement does not seem conclusive and, to our knowledge, there has not yet been a meta-analysis of the effect of peer feedback on general academic achievement in the STEM fields of higher education. Therefore, we conducted a meta-analysis to determine whether peer feedback is beneficial to STEM higher education students’ academic achievement. The final data set for the meta-analysis consisted of 286 effect sizes from 90 independent samples in 75 studies, with a total of over 14,000 participants. All effect sizes were calculated as Cohen’s d values. A random-effects model used to synthesise the effect sizes indicated a significant positive summary effect size (d = .421, SE = .037, 95% CI = .350, .493, p = .000). The variance of the true effect sizes (T2) was .069. The Qw value of 644.167 was significant (p = .000) and the I2 value of 88.512 was high. Therefore, in order to identify the source of the between-study heterogeneity, moderator analyses were conducted to evaluate the influence of various methodological quality characteristics and peer feedback intervention characteristics on the effect of a peer feedback intervention. The results of this study will provide researchers, policy makers and practitioners with the information they need to decide whether or not to use peer feedback and to be able to design peer feedback interventions for maximal effectiveness