General regression model: A "model-free" association test for quantitative traits allowing to test for the underlying genetic model

Most genome-wide association studies used genetic-model-based tests assuming an additive mode of inheritance, leading to underpowered association tests in case of departure from additivity. The general regression model (GRM) association test proposed by Fisher and Wilson in 1980 makes no assumption on the genetic model. Interestingly, it also allows formal testing of the underlying genetic model. We conducted a simulation study of quantitative traits to compare the power of the GRM test to the classical linear regression tests, the maximum of the three statistics (MAX), and the allele-based (allelic) tests. Simulations were performed on two samples sizes, using a large panel of genetic models, varying genetic models, minor allele frequencies, and the percentage of explained variance. In case of departure from additivity, the GRM was more powerful than the additive regression tests (power gain reaching 80%) and had similar power when the true model is additive. GRM was also as or more powerful than the MAX or allelic tests. The true simulated model was mostly retained by the GRM test. Application of GRM to HbA1c illustrates its gain in power. To conclude, GRM increases power to detect association for quantitative traits, allows determining the genetic model and is easily applicable.

Transmission of Type 2 diabetes to sons and daughters: the D.E.S.I.R. cohort

AIMS

To document the family transmission of Type 2 diabetes to men and women.

METHOD

The French D.E.S.I.R. cohort followed men and women over 9 years, with 3-yearly testing for incident Type 2 diabetes. First- and/or second-degree family histories of diabetes were available for 2187 men and 2282 women. Age-adjusted hazard ratios were estimated for various family members and groupings of family members, as well as for a genetic diabetes risk score, based on 65 diabetes-associated loci.

RESULTS

Over 9 years, 136 men and 63 women had incident Type 2 diabetes. The hazard ratios for diabetes associated with having a first-degree family member with diabetes (parents, siblings, children) differed between men [1.21 (95% CI 0.80, 1.85)] and women [3.02 (95% CI 1.83, 4.99); P_interaction =0.006]. The genetic risk score was predictive of diabetes in both men and women, with similar hazard ratios 1.10 (95% CI 1.06, 1.15) and 1.08 (95% CI 1.02, 1.14) respectively, for each additional at-risk allele. In women, the risk associated with having a family member with diabetes persisted after adjusting for the genetic score.

CONCLUSION

Women with a family history of diabetes (paternal or maternal) were at risk of developing Type 2 diabetes and this risk was independent of a genetic score; in contrast, for men, there was no association. Diabetes screening and prevention may need to more specifically target women with diabetes in their family, but further studies are required as the number of people with diabetes in this study was small.

Gamma-glutamyltransferase, fatty liver index and hepatic insulin resistance are associated with incident hypertension in two longitudinal studies

OBJECTIVE

We hypothesized that liver markers and the fatty liver index (FLI) are predictive of incident hypertension and that hepatic insulin resistance plays a role.

METHODS

The association between liver markers and incident hypertension was analysed in two longitudinal studies of normotensive individuals, 2565 from the 9-year data from an epidemiological study on the insulin resistance cohort and the 321 from the 3-year 'Relationship between Insulin Sensitivity and Cardiovascular disease' cohort who had a measure of endogenous glucose production. The FLI is calculated from BMI, waist circumference, triglycerides and gamma-glutamyltransferase (GGT) and the hepatic insulin resistance index from endogenous glucose production and fasting insulin.

RESULTS

The incidence of hypertension increased across the quartiles groups of both baseline GGT and alanine aminotransferase. After adjustment for sex, age, waist circumference, fasting glucose, smoking and alcohol intake, only GGT was significantly related with incident hypertension [standardized odds ratio: 1.21; 95% confidence interval (1.10-1.34); P = 0.0001]. The change in GGT levels over the follow-up was also related with an increased risk of hypertension, independently of changes in body weight. FLI analysed as a continuous value, or FLI at least 60 at baseline were predictive of incident hypertension in the multivariable model. In the RISC cohort, the hepatic insulin resistance index was positively related with the risk of 3-year incident hypertension [standardized odds ratio: 1.54 (1.07-2.22); P = 0.02].

CONCLUSION

Baseline GGT and FLI, as well as an increase in GGT over time, were associated with the risk of incident hypertension. Enhanced hepatic insulin resistance predicted the onset of hypertension and may be a link between liver markers and hypertension.

Longitudinal association of antidepressant medication use with metabolic syndrome: Results of a 9-year follow-up of the D.E.S.I.R. cohort study

OBJECTIVE

To examine longitudinal associations between antidepressant medication use and the metabolic syndrome (MetS).

METHODS

5014 participants (49.8% were men) from the D.E.S.I.R. cohort study, aged 30-65 years at baseline in 1994-1996, were followed over 9 years at 3-yearly intervals (1997-1999, 2000-2002, and 2003-2005). Antidepressant use and MetS, defined by the National Cholesterol Education Program Adult Treatment Panel III criteria (NCEP-ATP III) and the American Heart Association and the National Heart, Lung and Blood Institute (AHA/NHLBI) criteria, were assessed concurrently at four medical examinations.

RESULTS

In fully-adjusted longitudinal logistic regression analyses based on generalized estimating equations, antidepressant users had a 9% (p=0.011) and a 6% (p=0.036) greater annual increase in the odds of having the MetS defined by NCEP-ATP III and AHA/NHLBI criteria respectively. Sex-specific analyses showed that this association was confined to men only. When the different types of antidepressant were considered, men who used selective serotonin reuptake inhibitors (SSRIs), imipramine type antidepressants or "other" antidepressants had a 52% (p=0.028), 31% (p=0.011), and 16% (p=0.016) greater annual increase in the odds of having the MetS over time compared to non-users, respectively. These associations depended on the definition of the MetS.

CONCLUSIONS

Our longitudinal data showed that antidepressant use was associated with an increased odds of having the MetS in men but not in women and this was mainly for SSRIs, imipramine type and "other" antidepressants. People on antidepressants may need to be checked regularly for the elements of the metabolic syndrome treatable by change in diet, physical activity and/or by medication therapy.

Metabolomic Profile of Low-Copy Number Carriers at the Salivary α-Amylase Gene Suggests a Metabolic Shift Toward Lipid-Based Energy Production

Low serum salivary amylase levels have been associated with a range of metabolic abnormalities, including obesity and insulin resistance. We recently suggested that a low copy number at the AMY1 gene, associated with lower enzyme levels, also increases susceptibility to obesity. To advance our understanding of the effect of AMY1 copy number variation on metabolism, we compared the metabolomic signatures of high- and low-copy number carriers. We analyzed, using mass spectrometry and nuclear magnetic resonance (NMR), the sera of healthy normal-weight women carrying either low-AMY1 copies (LAs: four or fewer copies; n = 50) or high-AMY1 copies (HAs: eight or more copies; n = 50). Best-fitting multivariate models (empirical P < 1 × 10^-3) of mass spectrometry and NMR data were concordant in showing differences in lipid metabolism between the two groups. In particular, LA carriers showed lower levels of long- and medium-chain fatty acids, and higher levels of dicarboxylic fatty acids and 2-hydroxybutyrate (a known marker of glucose malabsorption). Taken together, these observations suggest increased metabolic reliance on fatty acids in LA carriers through β- and ω-oxidation and reduced cellular glucose uptake with consequent diversion of acetyl-CoA into ketogenesis. Our observations are in line with previously reported delayed glucose uptake in LA carriers after starch consumption. Further functional studies are needed to extrapolate from our findings to implications for biochemical pathways.

Gain-of-function Prolactin Receptor Variants Are Not Associated With Breast Cancer and Multiple Fibroadenoma Risk

CONTEXT

In a cohort of 95 women with multiple breast fibroadenomas (MFAs), we recently identified patients harboring germline heterozygous variants of the prolactin receptor (PRLR) exhibiting constitutive activity (PRLR_I146L and PRLR_I176V).

OBJECTIVE

This study sought to better delineate the potential role of PRLR gain-of-function variants in benign and malignant mammary tumorigenesis.

DESIGN

This was an observational study and transgenic mouse model analysis.

SETTING

The study took place at the Department of Endocrinology, Reproductive Disorders and Rare Gynecologic Diseases, Pitié Salpêtrière, Paris, and Inserm Unit 1151, Paris.

PATIENTS OR OTHER PARTICIPANTS

We generated a second MFA cohort (n = 71) as well as a group of control subjects (n = 496) and a cohort of women with breast cancer (n = 119). We also generated two transgenic mouse models carrying the coding sequences of human PRLR_I146L or PRLR_WT.

INTERVENTION

We aimed to determine the prevalence of PRLR variants in these three populations and to uncover any association of the latter with specific tumor pattern, especially in patients with breast cancer.

RESULTS

This study did not highlight a higher prevalence of PRLR variants in the MFA group and in the breast cancer group compared with control subjects. Transgenic mice expressing PRLR_I146L exhibited very mild histological mammary phenotype but tumors were never observed.

CONCLUSION

PRLR_I146L and PRLR_I176V variants are not associated with breast cancer or MFA risk. However, one cannot exclude that low but sustained PRLR signaling may facilitate or contribute to pathological development driven by oncogenic pathways. Long-term patient follow-up should help to address this issue.

Impact of statistical models on the prediction of type 2 diabetes using non-targeted metabolomics profiling

OBJECTIVE

Characterizing specific metabolites in sub-clinical phases preceding the onset of type 2 diabetes to enable efficient preventive and personalized interventions.

RESEARCH DESIGN AND METHODS

We developed predictive models of type 2 diabetes using two strategies. One strategy focused on the probability of incidence only and was based on logistic regression (MRS1); the other strategy accounted for the age at diagnosis of diabetes and was based on Cox regression (MRS2). We assessed 293 metabolites using non-targeted metabolomics in fasting plasma samples of 1,044 participants (including 231 incident cases over 9 years) used as training population; and fasting serum samples of 128 participants (64 incident cases versus 64 controls) used as validation population. We applied a LASSO-based variable selection aiming at maximizing the out-of-sample area under the receiver operating characteristic curve (AROC) and integrated AROC.

RESULTS

Sixteen and 17 metabolites were selected for MRS1 and MRS2, respectively, with AROC = 90% and 73% in the training and validation populations, respectively for MRS1. MRS2 had a similar performance and was significantly associated with a younger age of onset of type 2 diabetes (β = -3.44 years per MRS2 SD in the training population, p = 1.56 × 10(-7); β = -4.73 years per MRS2 SD in the validation population, p = 4.04 × 10(-3)).

CONCLUSIONS

Overall, this study illustrates that metabolomics improves prediction of type 2 diabetes incidence of 4.5% on top of known clinical and biological markers, reaching 90% in total AROC, which is considered the threshold for clinical validity, suggesting it may be used in targeting interventions to prevent type 2 diabetes.

Plasma Copeptin, AVP Gene Variants, and Incidence of Type 2 Diabetes in a Cohort From the Community

CONTEXT

Experimental data support a role for vasopressin in metabolic disorders.

OBJECTIVE

We investigated associations of plasma copeptin, a surrogate of vasopressin, and of allelic variations in the arginine vasopressin-neurophysin II gene with insulin secretion, insulin sensitivity, and the risk for impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM).

DESIGN, SETTING, AND PARTICIPANTS

We studied 5110 unrelated French men and women from a prospective cohort of the general population (Data from Epidemiological Study on the Insulin Resistance Syndrome cohort, 9-y follow-up). Six single nucleotide polymorphisms were genotyped.

MAIN OUTCOME MEASURE

Incidence of IFG or T2DM during follow-up.

RESULTS

The incidence of hyperglycemia (IFG/T2DM) during follow-up by quartiles of baseline plasma copeptin was 11.0% (Q1), 14.5% (Q2), 17.0% (Q3), and 23.5% (Q4), log-rank test P = .003. Participants in the upper quartile of plasma copeptin had significantly lower insulin sensitivity (homeostasis model assessment index) at baseline and during follow-up, as compared with other participants. Cox proportional hazards regression analyses showed significant associations of the CC genotype of rs6084264, the TT genotype of rs2282018, the C-allele of rs2770381, and the CC genotype of rs1410713 with the incidence of hyperglycemia. The genotypes associated with an increased risk of hyperglycemia were also associated with increased plasma copeptin in men but not in women.

CONCLUSIONS

High plasma copeptin was associated with reduced insulin sensitivity and an increased risk for IFG/T2DM diabetes in this community-based cohort. Moreover, in men, allelic associations support a causal role for vasopressin in these disorders.

[Promote better nutritional behaviours among shift workers with night shift]

AIM

Shift work, especially including a night shift, is associated with degradation of physical, social and psychosocial health as well as poor well-being. Food imbalance and low physical activity contributed to the negative effects on health. Our objective was to promote a healthier nutritional behaviour according to the French national nutrition and health program recommendations (PNNS).

METHODS

A one-year nutritional intervention with personalised dietetic counselling was proposed to 235 shift workers with night shift who came for a health prevention exam in one of the centres of the Institut Inter-Régional pour la Santé between 2009 and 2011. The intervention was three dietary interviews: at baseline with definition of goal setting, at 3 months for advice and support and at one-year for the evaluation. At 6 months, a personalised reminder letter was send. Compliance with the PNNS recommendations and level of physical activity were evaluated at baseline and at one-year by a self-administered questionnaire. Changes between baseline and follow-up were compared by paired t-tests or McNemar-tests.

RESULTS

The rate of follow-up was 57.4%. At the end of the study, subjects improved their compliance with PNNS guidelines concerning sweetened products (P<0.001), water (P=0.02) and salt (P=0.05), increased their leisure physical activity (P=0.001) and decreased their daily energy intakes (P<0.001).

CONCLUSION

A structured intervention can improve nutritional behaviours of shift workers. This intervention enabled to inform and alert on the risk related to this work schedule and promote better nutritional behaviours.

Deprivation and health risk indicators in full-time permanent workers

BACKGROUND

Association between deprivation and health is well established, particularly among unemployed or fixed-term contract or temporary contract subjects. This study aimed to assess if this relationship existed as well in full-time permanent workers.

METHODS

Biometrical, biological, behavioural and psychosocial health risk indicators and an individual deprivation score, the Evaluation of Precarity and Inequalities in Health Examination Centres score, were recorded from January 2007 to June 2008, in 34 905 full-time permanent workers aged 18-70 years, all volunteers for a free health examination. Comparisons of the behavioural, metabolic, cardiovascular and health risk indicators between quintiles of the deprivation score with adjustments on age and socioeconomic categories were made by covariance analysis or logistic regression.

RESULTS

For both genders, degradation of nutritional behaviours, metabolic and cardiovascular indicators and health appeared gradually with deprivation, even for deprivation score usually considered as an insignificant value. The absence of only one social support or one social network was associated with a degradation of health. Full-time permanent workers with the poorest health risk indicators had more frequent social exclusion signs. These results were independent of socioeconomic categories and age.

CONCLUSION

Understanding how deprivation influences health status may lead to more effective interventions to reduce social inequalities in health. The deprivation Evaluation of Precarity and Inequalities in Health Examination Centres score is a relevant tool to detect subjects who could benefit from preventive interventions. Our findings suggest that this deprivation score should be used as a health risk indicator even in full-time permanent workers. Assessing deprivation is useful to design and evaluate specific intervention programmes.

Novel modeling of reference values of cardiovascular risk factors in children aged 7 to 20 years

BACKGROUND AND OBJECTIVE

Most of the cardiovascular risk factors strongly associated with obesity and overweight vary with age and gender. However, few reference values are available for healthy European children. Our objective was to establish pediatric reference ranges for waist circumference, systolic and diastolic blood pressures, fasting lipid levels (total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides), glucose, and insulin.

METHODS

A representative sample of 1976 healthy French individuals (1004 female participants and 972 male participants) aged 7 to 20 years was used to obtain age- and gender-specific normal ranges for each of the above-listed cardiovascular risk factors, based on the Royston and Wright method.

RESULTS

Mean waist circumference increased with age in both genders and was slightly higher in males than in females. Whereas systolic blood pressure increased gradually with age, with the increase being steeper in males than in females, no gender effect was found for diastolic blood pressure, which was therefore modeled after pooling males and females. Total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride values varied little with age and gender. Glucose and insulin levels revealed pubertal peaks, which were sharper in females than in males, reflecting the normal insulin resistance during puberty.

CONCLUSIONS

These ranges can be used as references for European children to monitor cardiovascular risk factors and to plan interventions and education programs.

A genome-wide association search for type 2 diabetes genes in African Americans

African Americans are disproportionately affected by type 2 diabetes (T2DM) yet few studies have examined T2DM using genome-wide association approaches in this ethnicity. The aim of this study was to identify genes associated with T2DM in the African American population. We performed a Genome Wide Association Study (GWAS) using the Affymetrix 6.0 array in 965 African-American cases with T2DM and end-stage renal disease (T2DM-ESRD) and 1029 population-based controls. The most significant SNPs (n = 550 independent loci) were genotyped in a replication cohort and 122 SNPs (n = 98 independent loci) were further tested through genotyping three additional validation cohorts followed by meta-analysis in all five cohorts totaling 3,132 cases and 3,317 controls. Twelve SNPs had evidence of association in the GWAS (P<0.0071), were directionally consistent in the Replication cohort and were associated with T2DM in subjects without nephropathy (P<0.05). Meta-analysis in all cases and controls revealed a single SNP reaching genome-wide significance (P<2.5×10(-8)). SNP rs7560163 (P = 7.0×10(-9), OR (95% CI) = 0.75 (0.67-0.84)) is located intergenically between RND3 and RBM43. Four additional loci (rs7542900, rs4659485, rs2722769 and rs7107217) were associated with T2DM (P<0.05) and reached more nominal levels of significance (P<2.5×10(-5)) in the overall analysis and may represent novel loci that contribute to T2DM. We have identified novel T2DM-susceptibility variants in the African-American population. Notably, T2DM risk was associated with the major allele and implies an interesting genetic architecture in this population. These results suggest that multiple loci underlie T2DM susceptibility in the African-American population and that these loci are distinct from those identified in other ethnic populations.

Genomewide association study using a high-density single nucleotide polymorphism array and case-control design identifies a novel essential hypertension susceptibility locus in the promoter region of endothelial NO synthase

Essential hypertension is a multifactorial disorder and is the main risk factor for renal and cardiovascular complications. The research on the genetics of hypertension has been frustrated by the small predictive value of the discovered genetic variants. The HYPERGENES Project investigated associations between genetic variants and essential hypertension pursuing a 2-stage study by recruiting cases and controls from extensively characterized cohorts recruited over many years in different European regions. The discovery phase consisted of 1865 cases and 1750 controls genotyped with 1M Illumina array. Best hits were followed up in a validation panel of 1385 cases and 1246 controls that were genotyped with a custom array of 14 055 markers. We identified a new hypertension susceptibility locus (rs3918226) in the promoter region of the endothelial NO synthase gene (odds ratio: 1.54 [95% CI: 1.37-1.73]; combined P=2.58 · 10(-13)). A meta-analysis, using other in silico/de novo genotyping data for a total of 21 714 subjects, resulted in an overall odds ratio of 1.34 (95% CI: 1.25-1.44; P=1.032 · 10(-14)). The quantitative analysis on a population-based sample revealed an effect size of 1.91 (95% CI: 0.16-3.66) for systolic and 1.40 (95% CI: 0.25-2.55) for diastolic blood pressure. We identified in silico a potential binding site for ETS transcription factors directly next to rs3918226, suggesting a potential modulation of endothelial NO synthase expression. Biological evidence links endothelial NO synthase with hypertension, because it is a critical mediator of cardiovascular homeostasis and blood pressure control via vascular tone regulation. This finding supports the hypothesis that there may be a causal genetic variation at this locus.

Blood pressure loci identified with a gene-centric array

Raised blood pressure (BP) is a major risk factor for cardiovascular disease. Previous studies have identified 47 distinct genetic variants robustly associated with BP, but collectively these explain only a few percent of the heritability for BP phenotypes. To find additional BP loci, we used a bespoke gene-centric array to genotype an independent discovery sample of 25,118 individuals that combined hypertensive case-control and general population samples. We followed up four SNPs associated with BP at our p < 8.56 × 10(-7) study-specific significance threshold and six suggestively associated SNPs in a further 59,349 individuals. We identified and replicated a SNP at LSP1/TNNT3, a SNP at MTHFR-NPPB independent (r(2) = 0.33) of previous reports, and replicated SNPs at AGT and ATP2B1 reported previously. An analysis of combined discovery and follow-up data identified SNPs significantly associated with BP at p < 8.56 × 10(-7) at four further loci (NPR3, HFE, NOS3, and SOX6). The high number of discoveries made with modest genotyping effort can be attributed to using a large-scale yet targeted genotyping array and to the development of a weighting scheme that maximized power when meta-analyzing results from samples ascertained with extreme phenotypes, in combination with results from nonascertained or population samples. Chromatin immunoprecipitation and transcript expression data highlight potential gene regulatory mechanisms at the MTHFR and NOS3 loci. These results provide candidates for further study to help dissect mechanisms affecting BP and highlight the utility of studying SNPs and samples that are independent of those studied previously even when the sample size is smaller than that in previous studies.

Serum Concentrations of Insulin-like Growth Factor (IGF)-1 and IGF Binding Protein-3 (IGFBP-3), IGF-1/IGFBP-3 Ratio, and Markers of Bone Turnover: Reference Values for French Children and Adolescents and z-Score Comparability with Other References

BACKGROUND

A reference model for converting serum growth factor and bone metabolism markers into an SD score (SDS) is required for clinical practice. We aimed to establish reference values of serum insulin-like growth factor-1 (IGF-1) and IGF binding protein 3 (IGFBP-3) concentrations and bone metabolism markers in French children, to generate a model for converting values into SDS for age, sex, and pubertal stage.

METHODS

We carried out a cross-sectional study of 1119 healthy white children ages 6–20 years. We assessed concentrations of serum IGF-1, IGFBP-3, carboxyterminal telopeptide α1 chain of type I collagen (CrossLaps), and bone alkaline phosphatase concentrations and height, weight, and pubertal stage, and used semiparametric regression to develop a model.

RESULTS

A single regression model to calculate the SDSs with an online calculator was provided. A positive relationship was found between SDS for serum IGF-1 and IGFBP-3, IGF/IGFBP-3 mol/L ratio, and anthropometric parameters (P &lt; 0.0001), with slightly greater effects observed for height than for body mass index (BMI). There was a negative relationship between serum CrossLaps concentration and BMI, and a positive relationship between serum CrossLaps concentration and height. A comparison of serum IGF-1 reference databases for children showed marked variation as a function of age and pubertal group; smooth changes with age and puberty were observed only in our model.

CONCLUSIONS

This new model for the assessment of SDS reference values specific for age, sex, and pubertal stage may help to increase the diagnostic power of these parameters for the assessment of growth and bone metabolism disorders. This study also provides information about the physiological role of height and BMI for the interpretation of these parameters.

Are the same clinical risk factors relevant for incident diabetes defined by treatment, fasting plasma glucose, and HbA1c?

OBJECTIVE

To compare incidences and risk factors for diabetes using seven definitions, with combinations of pharmacological treatment, fasting plasma glucose (FPG) ≥7.0 mmol/L, and HbA(1c) ≥6.5%.

RESEARCH DESIGN AND METHODS

Participants aged 30-65 years from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort were followed for 9 years.

RESULTS

More men had incident diabetes as defined by FPG ≥7.0 mmol/L and/or treatment than by HbA(1c) ≥6.5% and/or treatment: 7.5% (140/1,867) and 5.3% (99/1,874), respectively (P < 0.009); for women incidences were similar: 3.2% (63/1,958) and 3.4% (66/1,954). Known risk factors predicted diabetes for almost all definitions. Among those with incident diabetes by FPG alone versus HbA(1c) alone, there were more men (78 vs. 35%), case patients were 8 years younger, and fewer were alcohol abstainers (12 vs. 35%) (all P < 0.005). A diabetes risk score discriminated well between those with and without incident diabetes for all definitions.

CONCLUSIONS

In men, FPG definitions yielded more incident cases of diabetes than HbA(1c) definitions, in contrast with women. An FPG-derived risk score remained relevant for HbA(1c)-defined diabetes.

Influence of blood glucose on heart rate and cardiac autonomic function. The DESIR study

OBJECTIVES

  To evaluate in a general population, the relationships between dysglycaemia, insulin resistance and metabolic variables, and heart rate, heart rate recovery and heart rate variability.

METHODS

  Four hundred and forty-seven participants in the Data from an Epidemiological Study on the Insulin Resistance syndrome (DESIR) study were classified according to glycaemic status over the preceding 9 years. All were free of self-reported cardiac antecedents and were not taking drugs which alter heart rate. During five consecutive periods: rest, deep breathing, recovery, rest and lying to standing, heart rate and heart rate varability were evaluated and compared by ANCOVA and trend tests across glycaemic classes. Spearman correlation coefficients quantified the relations between cardio-metabolic risk factors, heart rate and heart rate varability.

RESULTS

  Heart rate differed between glycaemic groups, except during deep breathing. Between rest and deep-breathing periods, patients with diabetes had a lower increase in heart rate than others (P(trend) < 0.01); between deep breathing and recovery, the heart rate of patients with diabetes continued to increase, for others, heart rate decreased (P(trend) < 0.009). Heart rate was correlated with capillary glucose and triglycerides during the five test periods. Heart rate variability differed according to glycaemic status, especially during the recovery period. After age, sex and BMI adjustment, heart rate variability was correlated with triglycerides at two test periods. Change in heart rate between recovery and deep breathing was negatively correlated with heart rate variability at rest, (r=-0.113, P < 0.05): lower resting heart rate variability was associated with heart rate acceleration.

CONCLUSIONS

  Heart rate, but not heart rate variability, was associated with glycaemic status and capillary glucose. After deep breathing, heart rate recovery was altered in patients with known diabetes and was associated with reduced heart rate variability. Being overweight was a major correlate of heart rate variability.

Low high density lipoprotein cholesterol: prevalence and associated risk-factors in a large French population

PURPOSE

High density lipoprotein-cholesterol (HDL-C) is a strong predictor of cardiovascular risk. We investigated the distribution of HDL-C in a French general population according to age, sex, and the risk factors associated with low HDL-C values.

METHODS

A group of 18,483 men and 22,047 women 16-79 years of age were investigated during a medical check-up. Relevant parameters were studied in three groups according to age and gender-specific percentile classes (≤5th [HDL₅] median and >95th). Gender-specific logistic regression models selected variables associated with HDL₅.

RESULTS

Using the National Cholesterol Education Program Adult Treatment Panel III criteria (threshold: 40 mg/dL in men, 50 mg/dL in women) the prevalence of low HDL-C was 11.1% and 26.4% in men and women and it decreased with age. Mean HDL-C levels increased with age. HDL₅ was positively associated with a sedentary lifestyle and deprivation (p < 0.00001) even after adjustment on alcohol consumption and smoking. Abdominal obesity, smoking, hypertriglyceridemia, hyperleucocytosis, and low alcohol consumption were associated with HDL₅ for both genders.

CONCLUSIONS

The prevalence of low HDL-C was similar to that observed in other Europeans but lower than in the United States. HDL₅ was associated with cardiovascular risk factors, metabolic syndrome, and social deprivation. A prevention policy to increase HDL-C levels should focus on reducing smoking and abdominal obesity, particularly in deprived subjects.

Hemoglobin A1c and fasting plasma glucose levels as predictors of retinopathy at 10 years: the French DESIR study

OBJECTIVE

To evaluate the predictive values of hemoglobin A(1c) (HbA(1c)) and fasting plasma glucose (FPG) for retinopathy 10 years after the baseline examination.

METHODS

Seven hundred men and women from the DESIR (Data From an Epidemiological Study on the Insulin Resistance Syndrome) Study underwent evaluation for retinopathy using a nonmydriatic digital camera. During the preceding 9 years, 235 had diabetes mellitus (treated or FPG level of ≥126 mg/dL at least once), 227 had an impaired FPG level (110-125 mg/dL) at least once, and 238 always had glucose levels within reference limits (<110 mg/dL).

RESULTS

Compared with those without retinopathy, the 44 participants with retinopathy at 10 years had higher baseline mean (SD) levels of FPG (130 [49] vs 106 [22] mg/dL) and HbA(1c) (6.4% [1.6%] vs 5.7% [0.7%]) (both, P < .001). The frequency of retinopathy at 10 years, standardized according to the distribution of glycemia across the entire DESIR population, was 3.6%. In our population, FPG levels of 108 and 116 mg/dL had positive predictive values of 8.4% and 14.0%, respectively, for retinopathy at 10 years; HbA(1c) levels of 6.0% and 6.5% had positive predictive values of 6.0% and 14.8%, respectively. After 10 years of follow-up, retinopathy was equally frequent in participants with impaired FPG levels and in those who became diabetic during the study (8.6% and 6.7%, respectively), lower than in those with diabetes at baseline (13.9%).

CONCLUSION

Because the positive predictive values for retinopathy increase sharply from 108 mg/dL for FPG and from 6.0% for HbA(1c) levels, these thresholds are proposed to identify those at risk of retinopathy 10 years later.

Decreased insulin secretion and increased risk of type 2 diabetes associated with allelic variations of the WFS1 gene: the Data from Epidemiological Study on the Insulin Resistance Syndrome (DESIR) prospective study

AIMS/HYPOTHESIS

We investigated associations of allelic variations in the WFS1 gene with insulin secretion and risk of type 2 diabetes in a general population prospective study.

METHODS

We studied 5,110 unrelated French men and women who participated in the prospective Data from Epidemiological Study on the Insulin Resistance Syndrome (DESIR) study. Additional cross-sectional analyses were performed on 4,472 French individuals with type 2 diabetes and 3,065 controls. Three single nucleotide polymorphisms (SNPs) were genotyped: rs10010131, rs1801213/rs7672995 and rs734312.

RESULTS

We observed statistically significant associations between the major alleles of the three variants and prevalent type 2 diabetes in the DESIR cohort at baseline. Cox analyses showed an association between the G-allele of rs10010131 and incident type 2 diabetes (HR 1.34, 95% CI 1.08-1.70, p = 0.007). Similar results were observed for the G-allele of rs1801213 and the A-allele of rs734312. The GGA haplotype was associated with an increased risk of diabetes as compared with the ACG haplotype (HR 1.26, 95% CI 1.04-1.42, p = 0.02). We also observed statistically significant associations of the three SNPs with plasma glucose, HbA(1c) levels and insulin secretion at baseline and throughout the study in individuals with type 2 diabetes or at risk of developing diabetes. However, no association was observed in those who remained normoglycaemic at the end of the follow-up. Associations between the three variants and type 2 diabetes were replicated in cross-sectional studies of type 2 diabetic patients in comparison with a non-diabetic control group.

CONCLUSIONS/INTERPRETATION

The most frequent haplotype at the haplotype block containing the WFS1 gene modulated insulin secretion and was associated with an increased risk of type 2 diabetes.

Mean and yearly changes in blood pressure with age in the metabolic syndrome: the DESIR study

Systolic and diastolic blood pressure (SBP; DBP) increase with age, but after 45 years of age, the yearly change in DBP (ΔDBP) tends to be smaller in comparison with the yearly change in SBP (ΔSBP), which increases with age. The effect of the metabolic syndrome (MetS) on this yearly change has never been explored. In a 9-year longitudinal cohort Data from an Epidemiologic Study on the Insulin Resistance syndrome (DESIR) study, we examined 1308 men and 1325 women, aged 30-65 years, who had never been treated for hypertension. SBP and DBP were measured at four examinations 3 years apart, and pulse pressure (PP) and yearly changes (ΔSBP, ΔDBP and ΔPP) were calculated. SBP and PP increased with age to a higher degree in patients with the MetS. In men and women with the MetS, DBP remained nearly constant, but in those without the MetS, DBP increased. After adjusting for baseline values, ΔSBP and ΔPP increased by 0.5 mm Hg per year for every additional 10 years from baseline. These correlations with age were similar for men and women, and the yearly change was always higher than in those with the MetS. In contrast, ΔDBP increased very slowly until 50 years of age and then decreased similarly for those with and without the MetS. The increase in PP with age, a marker of vascular aging, was determined to begin earlier in the present study than has been shown in the past, and the MetS amplified this effect. This new aspect of the MetS might modify clinical management leading to earlier drug treatment, particularly in regard to both endothelial dysfunction and increased arterial stiffness.

Twelve type 2 diabetes susceptibility loci identified through large-scale association analysis

By combining genome-wide association data from 8,130 individuals with type 2 diabetes (T2D) and 38,987 controls of European descent and following up previously unidentified meta-analysis signals in a further 34,412 cases and 59,925 controls, we identified 12 new T2D association signals with combined P<5x10(-8). These include a second independent signal at the KCNQ1 locus; the first report, to our knowledge, of an X-chromosomal association (near DUSP9); and a further instance of overlap between loci implicated in monogenic and multifactorial forms of diabetes (at HNF1A). The identified loci affect both beta-cell function and insulin action, and, overall, T2D association signals show evidence of enrichment for genes involved in cell cycle regulation. We also show that a high proportion of T2D susceptibility loci harbor independent association signals influencing apparently unrelated complex traits.

Genetic variability at the six transmembrane protein of prostate 2 locus and the metabolic syndrome: the data from an epidemiological study on the Insulin Resistance Syndrome (DESIR) study

CONTEXT

The six-transmembrane protein of prostate 2 (STAMP2) has been shown to be involved in insulin resistance in animal models, but in humans, its role is far from understood. Our hypothesis was that genetic variation of STAMP2 could be associated with insulin resistance phenotypes such as the metabolic syndrome (MetS) in humans.

OBJECTIVE

Our objective was to search for associations between STAMP2 polymorphisms and the MetS in humans.

SUBJECTS AND METHODS

Nine single-nucleotide polymorphisms (SNPs) were tested for associations with the International Diabetes Federation-defined MetS and its constituent parameters in 5212 French Caucasians from the prospective study, Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR), with a 9-yr follow-up. Methods included logistic regression and analysis of covariance adjusting for confounding variables and testing for interactions.

RESULTS

None of the SNPs was significantly associated with the prevalence or the incidence of the MetS. The rs12386756 was marginally associated with two parameters of the MetS [triglycerides (P = 0.04) and fasting glucose (P = 0.05)]. An interaction effect between this SNP and fat intake was observed on high-density lipoprotein-cholesterol levels (P = 0.01) and systolic blood pressure (P = 0.03) that is consistent with an interrelation between STAMP2 and nutrition. Three SNPs were associated with insulin levels, but these SNPs were not associated with other features of the MetS.

CONCLUSION

These findings suggest that the common polymorphisms of STAMP2 are unlikely to significantly contribute to the risk of the MetS in the general population, but relationships with insulin and interactions with fat intake need to be replicated.

Associations of the -344 T>C and the 3097 G>A polymorphisms of CYP11B2 gene with hypertension, type 2 diabetes, and metabolic syndrome in a French population

BACKGROUND

Aldosterone can affect both blood pressure (BP) and glucose metabolism. We assessed the association of two polymorphisms -344 T>C and the 3097 G>A in the aldosterone synthase gene (CYP11B2) with prevalent and incident hypertension (HT), type 2 diabetes (T2D), and the metabolic syndrome (MetS).

METHODS

We studied the 5,212 participants to D.E.S.I.R. (Data from Epidemiologic Study on the Insulin Resistance syndrome), a cohort from French general population. Genotyping was done by a TaqMan assay. Analysis of covariance, multivariate logistic regression (adjusted for age, MetS components) and haplotype analysis were performed.

RESULTS

The prevalences and 9-year incidences were 16.7 and 36.1% for HT, 2.6 and 6.2% for T2D, and 19.3 and 25.1% for the MetS. Risk for incident HT was reduced with the AA genotype of 3097 G>A, adjusted odds ratios (OR): 0.67; p = 0.04. The prevalence of HT was lower in women carrying the C allele of -344 T>C, OR 0.75; p = 0.03 for the TC genotype and 0.69; p = 0.03 for the CC genotype. In men, incident T2D was associated with both polymorphisms, adjusted OR for -344 T>C: 1.63; p = 0.04 for TC genotype and 2.12; p = 0.008 for CC genotype; for the 3097 G>A: the AA genotype was associated with a lower risk, OR 0.23; p = 0.02. In men, incident MetS was associated with 3097 G>A, OR: 0.57; p = 0.02 for AA genotype. Significant associations between haplotype combinations and the prevalence or incidence of the three diseases were also found.

CONCLUSION

The -344 T>C and 3097 G>A polymorphisms in the CYP11B2 are associated with T2D, hypertension and the MetS in European subjects with gender variations.

High baseline insulin levels associated with 6-year incident observed sleep apnea

OBJECTIVE

Obstructive sleep apnea is common in patients with type 2 diabetes, and its association with insulin and insulin resistance has been examined in cross-sectional studies. We evaluate risk factors for incident observed sleep apnea in a general population not selected for sleep disturbances.

RESEARCH DESIGN AND METHODS

A total of 1,780 men and 1,785 women, aged 33 to 68 years, from the cohort Data from an Epidemiologic Study on the Insulin Resistance Syndrome (D.E.S.I.R.) responded to the question, "Has someone said to you that you stop breathing during your sleep?" at baseline and 6 years. Anthropometric, clinical, and biological factors were recorded at both time points.

RESULTS

At baseline, 14% of men and 7% of women reported having observed sleep apnea (positive response to question); 6-year incidences were 14 and 6%, respectively. Age, anthropometric parameters, blood pressure, and sleep characteristics were all associated with prevalent, observed apnea episodes, in both sexes. Baseline waist circumference was the strongest predictor of incident apnea: standardized odds ratio (OR), adjusted for age and sex, 1.34 (95% CI 1.19-1.52). After adjustment for age, sex, and waist circumference, the standardized ORs for incident observed apnea were identical for fasting insulin and the homeostasis model assessment of insulin resistance: 1.31 (1.13-1.51) and 1.24 (1.09-1.41) for triglycerides and 1.52 (1.12-2.05) for smoking. Observed apnea at baseline was not associated with changes in anthropometric or biological parameters over the 6-year follow-up.

CONCLUSIONS

The most important baseline risk factor for incident apnea was adiposity. After accounting for adiposity, other risk factors were high insulin, insulin resistance, high triglycerides, and smoking, factors amenable to lifestyle intervention.

New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk

Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes.

Risk factors for incident type 2 diabetes in individuals with a BMI of <27 kg/m2: the role of gamma-glutamyltransferase. Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR)

AIMS/HYPOTHESIS

Risk factors for incident type 2 diabetes, in particular, hepatic markers, have rarely been studied in leaner individuals. We aimed to identify the metabolic and hepatic markers associated with incident diabetes in men and women with a BMI of <27 kg/m(2) and to compare them with those in individuals with a BMI of >or=27 kg/m(2).

METHODS

Risk factors for 9 year incident diabetes were compared in the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort. Comparisons were made between the 2,947 participants with a BMI of <27 kg/m(2) and the 879 with a BMI of >or=27 kg/m(2).

RESULTS

There were 92 incident cases of diabetes in individuals with a BMI of <27 kg/m(2) and 111 in those with a BMI of >or=27 kg/m(2). Among those who were not markedly overweight, classical biological markers were associated with 9 year incident diabetes, glycaemia being the strongest predictor. gamma-Glutamyltransferase (GGT), either considered as a continuous variable or at levels >or=20 U/l, was associated with incident diabetes, with a stronger effect in the BMI <27 kg/m(2) group: OR 1.59 (95% CI 1.29-1.97, p < 0.001) in comparison with OR 1.07 (95% CI 0.82-1.38, p = 0.63) for those with a BMI of >or=27 kg/m(2) (results after adjustment for alcohol intake, alanine aminotransferase, waist circumference and the HOMA insulin resistance index).

CONCLUSIONS/INTERPRETATION

In individuals with a BMI of <27 kg/m(2), GGT was the strongest predictor of diabetes after fasting hyperglycaemia. This association with incident diabetes remained after adjustment for conventional markers of insulin resistance, suggesting potential interactions between GGT, enhanced hepatic neoglucogenesis and/or early alterations of insulin secretion.

Genetic variant in HK1 is associated with a proanemic state and A1C but not other glycemic control-related traits

OBJECTIVE

A1C is widely considered the gold standard for monitoring effective blood glucose levels. Recently, a genome-wide association study reported an association between A1C and rs7072268 within HK1 (encoding hexokinase 1), which catalyzes the first step of glycolysis. HK1 deficiency in erythrocytes (red blood cells [RBCs]) causes severe nonspherocytic hemolytic anemia in both humans and mice.

RESEARCH DESIGN AND METHODS

The contribution of rs7072268 to A1C and the RBC-related traits was assessed in 6,953 nondiabetic European participants. We additionally analyzed the association with hematologic traits in 5,229 nondiabetic European individuals (in whom A1C was not measured) and 1,924 diabetic patients. Glucose control-related markers other than A1C were analyzed in 18,694 nondiabetic European individuals. A type 2 diabetes case-control study included 7,447 French diabetic patients.

RESULTS

Our study confirms a strong association between the rs7072268-T allele and increased A1C (beta = 0.029%; P = 2.22 x 10(-7)). Surprisingly, despite adequate study power, rs7072268 showed no association with any other markers of glucose control (fasting- and 2-h post-OGTT-related parameters, n = 18,694). In contrast, rs7072268-T allele decreases hemoglobin levels (n = 13,416; beta = -0.054 g/dl; P = 3.74 x 10(-6)) and hematocrit (n = 11,492; beta = -0.13%; P = 2.26 x 10(-4)), suggesting a proanemic effect. The T allele also increases risk for anemia (836 cases; odds ratio 1.13; P = 0.018).

CONCLUSIONS

HK1 variation, although strongly associated with A1C, does not seem to be involved in blood glucose control. Since HK1 rs7072268 is associated with reduced hemoglobin levels and favors anemia, we propose that HK1 may influence A1C levels through its anemic effect or its effect on glucose metabolism in RBCs. These findings may have implications for type 2 diabetes diagnosis and clinical management because anemia is a frequent complication of the diabetes state.

[Drug treatment of cardiovascular risk factors over six years of following the French DESIR cohort]

OBJECTIVE

To describe the treatment of cardiovascular risk factors within the context of a cohort study of adults, according to the risk estimated by the Framingham equation.

METHOD

This prospective study, DESIR, followed 1526 men and 1652 women for six years. At the time of the study's initiation, all participants were aged 35 to 65, and none were being treated for hypertension or dyslipemia. Treatments for hypertension and dyslipemia initiated during the study were analyzed according to categories of cardiovascular risk based on the Framingham scale.

RESULTS

At baseline, 24% of men and 5% of women had an estimated 10 years cardiovascular risk (for CHD) higher or equal to 10%. Three years later, only 19% of these men and 36% of these women had been treated, while 6% of men and 9% of women at risk < 10% had also been treated well. At six years, one third of men at high risk at baseline and/or at three years were treated, against half of the women.

CONCLUSION

Despite a significant effort to communicate the importance of addressing and treating the individual risk factors, the currently prescribed treatments remain inadequate, especially given the necessity to treat them based on the assessment of the overall cardiovascular risk.

Genetic variant near IRS1 is associated with type 2 diabetes, insulin resistance and hyperinsulinemia

Genome-wide association studies have identified common variants that only partially explain the genetic risk for type 2 diabetes (T2D). Using genome-wide association data from 1,376 French individuals, we identified 16,360 SNPs nominally associated with T2D and studied these SNPs in an independent sample of 4,977 French individuals. We then selected the 28 best hits for replication in 7,698 Danish subjects and identified 4 SNPs showing strong association with T2D, one of which (rs2943641, P = 9.3 x 10(-12), OR = 1.19) was located adjacent to the insulin receptor substrate 1 gene (IRS1). Unlike previously reported T2D risk loci, which predominantly associate with impaired beta cell function, the C allele of rs2943641 was associated with insulin resistance and hyperinsulinemia in 14,358 French, Danish and Finnish participants from population-based cohorts; this allele was also associated with reduced basal levels of IRS1 protein and decreased insulin induction of IRS1-associated phosphatidylinositol-3-OH kinase activity in human skeletal muscle biopsies.

Performance of immunochemical faecal occult blood test in colorectal cancer screening in average-risk population according to positivity threshold and number of samples

Immunochemical faecal occult blood tests (I-FOBT) detect more effectively advanced neoplasia than guaiac tests (G-FOBT). The study aim was to compare the performance of an I-FOBT whilst varying the positivity threshold and considering four analysis modalities: one sample was performed (MG(1)), two samples were performed and at least one sample was positive (MG(2+)), both samples were positive (MG(2++)) or the mean of the two samples' log-transformed haemoglobin contents exceeded the cutoff (MG(2m)). Screening for colorectal cancer using both G-FOBT and two samples' I-FOBT was performed by an average-risk population sample of 20,322 subjects. Among the 1,615 subjects with at least one positive test, 1,277 had a satisfactory colonoscopy result; 43 invasive cancers and 270 high-risk adenomas were detected. The I-FOBT was reinterpreted under each analysis modality (a random selection of one sample led to MG(1)). For all modalities, increasing the positivity threshold decreased sensitivity and increased specificity. The relative ROC curves (in reference to G-FOBT) demonstrated similar performance for MG(1) and MG(2+), and improved performance for MG(2m). MG(2++) sensitivity was limited within the range of positivity thresholds evaluated. For any specificity, MG(2m) provided the highest sensitivity. For any sensitivity, MG(2m) provided the highest specificity. For any positivity rate, MG(2m) provided both the highest sensitivity and specificity. This study suggests the replacement of MG(2+) by MG(1) or, for even better performance, by MG(2m) provided that two samples are performed with similar participation (which should be explored). The targeted positivity rate could then be achieved by choosing the positivity threshold.

A rare variant in the visfatin gene (NAMPT/PBEF1) is associated with protection from obesity

Visfatin was recently reported as a novel adipokine encoded by the NAMPT (PBEF1) gene. This study was aimed at investigation of the possibility that single-nucleotide polymorphisms (SNPs) in the visfatin gene are associated with either obesity or type 2 diabetes (T2D). A set of eight "tag-SNPs" were selected and ABI SNPlex assays designed for genotyping purposes. A total of 1,709 severely obese subjects were typed (896 class III obese adults and 813 children) together with 2,367 T2D individuals and 2,850 controls. For quantitative trait analysis, an additional 2,362 subjects were typed for rs10487818 from a general population sample. One rare SNP, rs10487818, located in intron 4 of NAMPT was associated with severe obesity, with a minor allele frequency of 1.6% in controls, 0.4% in the class III obese adults and, remarkably, 0% in the severely obese children. A highly significant association was observed for the presence or absence of the rare allele, i.e., (A,A) vs. (A,T + T,T) genotypes, in children (P = 6 x 10(-9)) and in adults (P = 8 x 10(-5)). No other significant (P < 0.05) association was observed with obesity or T2D for this or any other SNP. No association with BMI or waist-to-hip ratio was observed in a general population sample (n = 5,212). This is one of the first rare SNPs shown to be protective against a common polygenic disease and provides further evidence that rare alleles of strong effect can contribute to complex diseases such as severe obesity.

Sex hormone-binding globulin predicts the incidence of hyperglycemia in women: interactions with adiponectin levels

OBJECTIVE

Previous evidence has suggested that a low sex hormone-binding globulin (SHBG) concentration is associated with insulin-resistance and a low adiponectin concentration. We investigated the association between SHBG and the risk of hyperglycemia in each sex and we determined potential interactions between SHBG and adiponectin levels in the development of dysglycemia.

DESIGN

We used a nested case-control design in the large prospective study, Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR). We studied 227 men and women who were normoglycemic at baseline but hyperglycemic at 3 years (glycemia > or = 6.1 mmol/l or type 2 diabetes). They were matched for sex, age, and body mass index with 227 subjects who remained normoglycemic at 3 years.

RESULTS

At baseline, the concentration of SHBG was significantly lower in women who subsequently developed hyperglycemia than in those who remained normoglycemic, with no difference for men. In multiple regression, SHBG at baseline was as an independent determinant of plasma adiponectin levels, in both women (P<0.0001) and men (P=0.002). In multivariate conditional logistic regression taking into account physical activity and changes in waist circumference over the follow-up, plasma SHBG remained significantly associated with the development of hyperglycemia in women but not in men. These associations persisted after adjustment for fasting insulinemia, high fasting glucose, and adiponectin levels.

CONCLUSIONS

These findings suggest that a low SHBG level is a strong risk marker for dysglycemia in women, independently of both adiponectinemia and insulinemia. SHBG may therefore improve the identification of women at risk of diabetes.

Center effect on ankle-brachial index measurement when using the reference method (Doppler and manometer): results from a large cohort study

BACKGROUND

The ankle-brachial index (ABI) is a simple and noninvasive tool used to detect peripheral arterial disease (PAD). We aimed to assess, in a French multicenter cohort, the center effect associated with arterial pressure (AP) and ABI measurements using the reference method and using a semiautomatic device.

METHODS

This study included baseline and 9-year follow-up data from 3,664 volunteers of 10 health examination centers of the DESIR (Data from an Epidemiological Study on the Insulin Resistance) syndrome French cohort. Ankle and brachial AP were measured at inclusion by the reference method (a mercury sphygmomanometer coupled with a Doppler probe for ankle measurements) and at 9 years by a semiautomatic device (Omron HEM-705CP). The center effect was assessed by the intraclass correlation coefficient (ICC), ratio of the between-center variance to the total variance of the measurement.

RESULTS

At inclusion, the sample mean age was 47.5 (s.d. 9.9) years; 49.3% were men. Although ICCs were smaller than 0.05 for brachial AP measurements, they were close to 0.18 and 0.20 for ankle systolic AP (SAP) and ABI measurements, respectively, when the reference method was used. No center effect for measures other than ankle SAP was detected. With the semiautomatic device method, all ICCs, including those for ankle SAP and ABI measurements, were between 0.005 and 0.04.

CONCLUSIONS

We found an important center effect on ABI measured with a sphygmomanometer and a Doppler probe but not a semiautomatic device. A center effect should be taken into account when planning any multicenter study on ABI measurement.

G-allele of intronic rs10830963 in MTNR1B confers increased risk of impaired fasting glycemia and type 2 diabetes through an impaired glucose-stimulated insulin release: studies involving 19,605 Europeans

OBJECTIVE

Genome-wide association studies have identified several variants within the MTNR1B locus that are associated with fasting plasma glucose (FPG) and type 2 diabetes. We refined the association signal by direct genotyping and examined for associations of the variant displaying the most independent effect on FPG with isolated impaired fasting glycemia (i-IFG), isolated impaired glucose tolerance (i-IGT), type 2 diabetes, and measures of insulin release and peripheral and hepatic insulin sensitivity.

RESEARCH DESIGN AND METHODS

We examined European-descent participants in the Inter99 study (n = 5,553), in a sample of young healthy Danes (n = 372), in Danish twins (n = 77 elderly and n = 97 young), in additional Danish type 2 diabetic patients (n = 1,626) and control subjects (n = 505), in the Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) study (n = 4,656), in the North Finland Birth Cohort 86 (n = 5,258), and in the Haguenau study (n = 1,461).

RESULTS

The MTNR1B intronic variant, rs10830963, carried most of the effect on FPG and showed the strongest association with FPG (combined P = 5.3 x 10(-31)) and type 2 diabetes. The rs10830963 G-allele increased the risk of i-IFG (odds ratio [OR] 1.64, P = 5.5 x 10(-11)) but not i-IGT. The G-allele was associated with a decreased insulin release after oral and intravenous glucose challenges (P < 0.01) but not after injection of tolbutamide. In elderly twins, the G-allele associated with hepatic insulin resistance (P = 0.017).

CONCLUSIONS

The G-allele of MTNR1B rs10830963 increases risk of type 2 diabetes through a state of i-IFG and not through i-IGT. The same allele associates with estimates of beta-cell dysfunction and hepatic insulin resistance.

Smallness for gestational age interacts with high mobility group A2 gene genetic variation to modulate height

OBJECTIVE

Height variability is largely under genetic control, although identifying the genetic variants involved has been until recently challenging. Smallness for gestational age (SGA) is a risk factor for adult short stature. Genome-wide association studies have identified a single nucleotide polymorphism (SNP) (rs1042725) in the high mobility group A2 gene (HMGA2) that consistently associates with height variability but its interaction with SGA is unknown.

DESIGN

We assess the contribution of rs1042725 SNP and height variability in a French population and the impact of rs1042725 on SGA status at birth and height at adulthood in SGA individuals.

METHODS

We genotyped rs1042725 in 4710 healthy participants from the Data from an Epidemiological Study on the Insulin Resistance syndrome (DESIR) cohort, 743 normal birth weight and 660 SGA individuals from the Haguenau study.

RESULTS

rs1042725 is associated with increased height in the cohort participants (0.36 cm 95% CI (0.12-0.61) per C allele, P=0.004) but not with the SGA status or birth length. Interestingly, rs1042725 had a stronger effect on height in SGA participants (0.94 cm 95% CI (0.24-1.64) per C allele, P=0.009), especially in men (1.45 cm 95% CI (0.44-2.46) per C allele, P=0.005) in whom rs1042725 may explain 3% of height variability. SGA men carrying at least one C allele copy experienced more frequent catch-up in height (P(add)=0.07; P(dom)=0.03).

CONCLUSIONS

Our study supports further the contribution of HMGA2 rs1042725 to height variability in European populations and shows an increased effect on height in SGA individuals where this variant favors height catch-up.

Comparison of a guaiac and an immunochemical faecal occult blood test for the detection of colonic lesions according to lesion type and location

We investigated variations in sensitivity of an immunochemical (I-FOBT) and a guaiac (G-FOBT) faecal occult blood test according to type and location of lesions in an average-risk 50- to 74-year-old population. Screening for colorectal cancer by both non-rehydrated Haemoccult II G-FOBT and Magstream I-FOBT was proposed to a sample of 20 322 subjects. Of the 1615 subjects with at least one positive test, colonoscopy results were available for 1277. A total of 43 invasive cancers and 270 high-risk adenomas were detected. The gain in sensitivity associated with the I-FOBT was calculated using the ratio of sensitivities (RSN) according to type and location of lesions, and amount of bleeding. The gain in sensitivity by using I-FOBT increased from invasive cancers (RSN=1.48 (1.16–4.59)) to high-risk adenomas (RSN=3.32 (2.70–4.07)), and was inversely related to the amount of bleeding. Among cancers, the gain in sensitivity was confined to rectal cancer (RSN=2.09 (1.36–3.20)) and concerned good prognosis cancers, because they involve less bleeding. Among high-risk adenomas, the gain in sensitivity was similar whatever the location. This study suggests that the gain in sensitivity by using an I-FOBT instead of a G-FOBT greatly depends on the location of lesions and the amount of bleeding. Concerning cancer, the gain seems to be confined to rectal cancer.

Trends in the prevalence of obesity in employed adults in central-western France: a population-based study, 1995-2005

OBJECTIVE

The overall trend of obesity prevalence has increased during the last decades, even in France which has one of the lowest prevalence in Europe. The aim of this study was to assess, according to socioeconomic status (SES), whether a shift in the obesity prevalence trends could be observed since the French National Nutrition and Public Health Program was implemented in 2001.

METHODS

Standardised cross-sectional repeated population-based data from the French Social Security Health Examination Centers in the central-western region of France (n=339,882). We examined regression slopes (95% CI) of overall and abdominal obesity from 1995 to 2005 according to SES. We also compared slopes within each SES between 1995-2001 and 2001-2005.

RESULTS

After standardisation to the French age distribution, 6.9% of men and 6.4% of women were obese in 1995 and 8.9% and 8.6% in 2005, respectively. Abdominal adiposity concerned 5.6% of men and 8.5% of women in 1995 and 9.5% and 14.3% in 2005. Obesity prevalence regression slopes between 1995 and 2005 increased in all SES categories, except management professionals in both genders and office/service personnel male who were stable. Significant regression slopes before 2001 became non-significant afterward in office/service personnel males for obesity prevalence; and for abdominal obesity in manual workers women and office/service personnel (p=0.05, in men).

CONCLUSIONS

Our data confirm the overall epidemic rise in the obesity prevalence trends during the last decade, except in management professionals and office/service personnel men. Obesity prevalence trends in office/service personnel and manual workers women for abdominal obesity were also observed to stabilise since 2001. We could hypothesize that the National Nutrition and Public Health Program may partly be involved in this decreasing trend among office/service personnel mainly. Policymakers should take into account these data to assess the effectiveness of obesity prevention public-health strategies in the future.