Confirmation of associations between ion channel gene SNPs and QTc interval duration in healthy subjects

Population-based association studies have identified several polymorphic variants in genes encoding ion channel subunits associated with the electrocardiographic heart-rate-corrected QT (QTc) length in healthy populations of Caucasian origin (KCNH2 rs1,805,123 (K897 T) and rs3,815,459, SCN5A rs1,805,126 (D1,819D), 1,141-3 C>A, rs1,805,124 (H558R), and IVS24+116 G>A, KCNQ1 rs757,092, KCNE1 IVS2-128 G>A and rs1,805,127 (G38S), and KCNE2 rs2,234,916 (T8A)). However, few of these results have been replicated in independent populations. We tested the association of SNPs KCNQ1 rs757,092, KCNH2 rs3,815,459, SCN5A IVS24+116 G>A, KCNE1 IVS2-128 G>A and KCNE2 rs2,234,916 with QTc length in two groups of 200 subjects presenting the shortest and the longest QTc from a cohort of 2,008 healthy subjects. All polymorphisms were in Hardy-Weinberg equilibrium in both groups. The minor allele SCN5A IVS24+116 A was more frequent in the group of subjects with the shortest QTc, whereas the minor alleles KCNQ1 rs757,092 G and KCNH2 rs3,815,459 A were more frequent in the group with the longest QTc. There was no significant difference for KCNE1 IVS2-128 G>A and KCNE2 rs2,234,916 between the two groups. Haplotype analysis showed a twofold increased risk of QTc lengthening for carriers of the haplotype, combining alleles C and A of the two common KCNE1 SNPs, IVS2-129 C>T (rs2,236,609) and rs1,805,127 (G38S), respectively. In conclusion, our study confirms the reported associations between QTc length and KCNQ1 rs757,092 and KCNH2 rs3,815,459.

Five-year predictive factors of type 2 diabetes in men with impaired fasting glucose

AIM

The outcome of 743 French men (age 20-60) with impaired fasting glucose (IFG) [blood glucose 6.1-6.9 mmol/l] at T1 was evaluated 5 years later, at T2.

METHODS

Personal and family medical history, smoking, nutritional habits, physical activity, blood pressure, body mass index (BMI) and waist girth, fasting biological data were collected at T1 and T2. Predictive factors for developing diabetes were compared between those who returned to normal fasting glucose and those who had diabetes, before and after adjustment for age, BMI, glucose and triglyceride (TG) levels.

RESULTS

At T2, 44%, 39%, 17% were classified as normal fasting plasma glucose (FPG), IFG or diabetic, respectively. Odd ratios for diabetes were 4.2 for men with a family history of diabetes (FHD), 3.4 if BMI > or = 25 kg/m(2), 2.9 if waist girth > or = 90 cm, 2.8 if TG > or = 2 mmol/l and 1.9 if no daily dairy products were eaten. Still significant after adjustment for age, BMI, glucose and TG levels were: FHD (P=0.001), no daily dairy products (P=0.001), high alcohol intake (P=0.02) and low physical activity (P = 0.02).

CONCLUSION

No daily dairy products, high alcohol intake and low physical activity were independent predictive factors of a 5-year onset of diabetes after adjusting for BMI, FHD, triglyceride and glucose levels at baseline. For a better prevention of diabetes, these findings give clues for behaviour modifications as soon as IFG is detected.

Prévalence des symptômes du syndrome d’apnées du sommeil. Étude dans une population française d’âge moyen

OBJECTIVE

To study the prevalence of symptoms of sleep apnoea syndrome (SAS) in a large French middle-aged population and to establish what proportion have symptoms that justify further investigation with a sleep study.

METHODS

We performed a cross-sectional study of 2,195 men and 2,247 women, 33 to 69 year old (DESIR. cohort) recording responses to a self-administered "sleep" questionnaire and a general questionnaire including socio-economic characteristics and lifestyle factors.

RESULTS

The prevalence of symptoms in men and women were respectively: snoring frequently (28%, 14%), frequent daytime sleepiness (14%, 18%) and frequent apnoeas (5%, 2%). Overall, 8.5% of men and 6.3% of women reported a pattern of symptoms suggestive of OSA, as they snored and had daytime sleepiness and/or apnoeas. This pattern was associated, for both sexes, with age, body mass index and after adjustment on these two factors, to a mediocre self-reported health status and treatment with benzodiazepines or other sedatives. For men only, the OSA pattern of symptoms was also associated with, hypertension, alcohol consumption and smoking.

CONCLUSION

Snoring, daytime hypersomnolence and witnessed apnoeas are symptoms frequently observed in the general population. Subjects with a combination of these abnormalities suggesting a high probability of sleep apnoea syndrome and in whom a sleep study is warranted represent 7.5% of the adult population.

Comparison of a guaiac based and an immunochemical faecal occult blood test in screening for colorectal cancer in a general average risk population

BACKGROUND

The guaiac faecal occult blood test (G-FOBT) is recommended as a screening test for colorectal cancer but its low sensitivity has prevented its use throughout the world.

METHODS

We compared the performances of the reference G-FOBT (non-rehydrated Hemoccult II test) and the immunochemical faecal occult blood test (I-FOBT) using different positivity cut-off values in an average risk population sample of 10,673 patients who completed the two tests. Patients with at least one test positive were asked to undergo colonoscopy.

RESULTS

Using the usual cut-off point of 20 ng/ml haemoglobin, the gain in sensitivity associated with the use of I-FOBT (50% increase for cancer and 256% increase for high risk adenoma) was balanced by a decrease in specificity. The number of extra false positive results associated with the detection of one extra advanced neoplasia (cancer or high risk adenoma) was 2.17 (95% confidence interval 1.65-2.85). With a threshold of 50 ng/ml, I-FOBT detected more than twice as many advanced neoplasias as the G-FOBT (ratio of sensitivity = 2.33) without any loss in specificity (ratio of false positive rate = 0.99). With a threshold of 75 ng/ml, associated with a similar positivity rate to G-FOBT (2.4%), the use of I-FOBT allowed a gain in sensitivity of 90% and a decrease in the false positive rate of 33% for advanced neoplasia.

CONCLUSIONS

Evidence in favour of the substitution of G-FOBT by I-FOBT is increasing, the gain being more important for high risk adenomas than for cancers. The automated reading technology allows choice of the positivity rate associated with an ideal balance between sensitivity and specificity.

Comment on "A common genetic variant is associated with adult and childhood obesity"

Herbert et al. (Reports, 14 April 2006, p. 279) reported an association between the INSIG2 gene variant rs7566605 and obesity in four sample populations, under a recessive model. We attempted to replicate this result in 10,265 Caucasian individuals, combining family-based, case-control, and general population studies, but found no support for a major role of this variant in obesity.

RETRACTED: Estimation of height from knee-heel length in middle age Caucasian adults

This article has been retracted consistent with Article in press policy. Please see . The Publisher apologises for any inconvenience this may cause.

ABCA1 single nucleotide polymorphisms on high-density lipoprotein-cholesterol and overweight: the D.E.S.I.R. study

The adenosine triphosphate-binding cassette A1 (ABCA1) gene plays a key role in reverse cholesterol transport. Some ABCA1 gene polymorphisms have been associated with high-density lipoprotein-cholesterol (HDL-C) concentrations. The aim of this study was to assess the effect of three polymorphisms, C69T, G378C, and G1051A (R219K), on HDL-C levels and their interaction with BMI in more than 5000 French whites from the D.E.S.I.R. (Data from an Epidemiological Study on the Insulin Resistance syndrome) cohort study. The T allele of the C69T single nucleotide polymorphism (SNP) was associated with higher HDL-C levels in normal-weight men (BMI <25 kg/m(2)). The C allele of the G378C SNP was associated with lower HDL-C in overweight subjects (BMI > or =25 kg/m(2)). For the G1051A SNP, in the normal-weight group, the minor A allele was significantly associated with higher HDL-C levels. In contrast, in overweight people, the minor allele was associated with lower HDL-C levels. After accounting for multiple testing, empiric p values remained significant for the associations between G378C SNP and HDL-C in the overweight group and between G1051A SNP and HDL-C in the normal-weight group. This study suggests that ABCA1 gene polymorphisms modulate HDL-C concentrations, in interaction with BMI, and, thus, they might influence cardiovascular risk in the general population.

Ferritin and transferrin are both predictive of the onset of hyperglycemia in men and women over 3 years: the data from an epidemiological study on the Insulin Resistance Syndrome (DESIR) study

OBJECTIVE

The aim of the present work was to determine, in a cohort of men and women, whether ferritin and transferrin were associated with glucose metabolism and whether they were predictive of the onset of hyperglycemia (impaired fasting glycemia or type 2 diabetes) after 3 years of follow-up.

RESEARCH DESIGN AND METHODS

Among 4,501 subjects from the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort, 1,277 subjects (644 men and 633 women) were randomly selected for the analysis of iron biomarkers at baseline and at 3 years. In addition, to determine whether these parameters were relevant to pathological changes, all 231 subjects normoglycemic at baseline and hyperglycemic 3 years later were analyzed for iron biomarkers.

RESULTS

At baseline, plasma ferritin concentrations were positively correlated with fasting insulin and fasting glucose in the 1,277 subjects. Although transferrin and ferritin were negatively correlated, transferrin was also positively correlated with fasting insulinemia. Baseline ferritin concentration was an independent predictor of an increase in insulin concentration over a 3-year period (P = 0.002). Further, baseline ferritin and transferrin were independently associated with the onset of hyperglycemia over a 3-year period in the whole population (P < 0.001 for both) and in each sex.

CONCLUSIONS

Although negatively correlated, both transferrin and ferritin were positively associated with the onset of abnormalities in glucose metabolism in a prospective study. These results further support the hypothesis of a causative role of iron metabolism in the onset of insulin resistance and type 2 diabetes.

Waist circumference and the metabolic syndrome predict the development of elevated albuminuria in non-diabetic subjects: the DESIR Study

OBJECTIVE

Metabolic determinants of microalbuminuria remain poorly understood in non-diabetic individuals and particularly in women. We investigated in both sexes whether an elevated waist circumference (WC) or the presence of the metabolic syndrome (MetS) predict the development of elevated albuminuria at 6 years.

DESIGN AND PATIENTS

We studied 2738 subjects from the DESIR cohort without microalbuminuria or diabetes at baseline and who were followed up for 6 years.

RESULTS

At 6 years, 254 individuals [9.3%; 95% confidence interval (CI) 8.2-10.4%] had developed elevated albuminuria (> or = 20 mg/l), which was significantly and positively associated with WC and blood pressure, but not with fasting glucose, lipids or body mass index in either sex. In both sexes, subjects with a high WC or with MetS at baseline were more likely to develop elevated albuminuria at 6 years compared with those with a normal WC or absence of MetS. In multivariate logistic analysis, WC as a continuous variable or a WC of 94 cm or greater for men and a WC greater than 88 cm for women were predictive of the development of elevated albuminuria, after adjusting for age, hypertension, the use of angiotensin-converting enzyme inhibitors, fibrinogen and glycaemia. MetS was a risk factor for elevated albuminuria in men (odds ratio 1.87; 95% CI 1.25-2.81), with differences according to the MetS definition.

CONCLUSION

Abdominal adiposity is related to the development of elevated albuminuria in both sexes, suggesting that the measurement of WC may improve the identification of non-diabetic individuals at risk of developing microalbuminuria and emphasizing the interest of screening for albuminuria among those with MetS.

[Larger waist circumference is a predictive factor for the occurrence of microalbuminuria in a non-diabetic population]

Obesity and insulin resistance are directly associated with the presence of microalbuminuria. However, the prospective relationship between abdominal adiposity and the occurrence of micro-albuminuria has been little studied in a non-diabetic population. From the DESIR cohort, we examined whether waist circumference was associated with the incidence of micro-albuminuria at 6 years (D6). The study evaluated 2738 non-diabetic subjects without micro-albuminuria at inclusion who were then followed prospectively. At 6 years, 254 individuals (9.3%) had developed pathological micro-albuminuria (> or =20 mg/l) measured at micturation. In both sexes, the incidence of micro-albuminuria was associated with increased waist circumference and blood pressure, but not with blood glucose levels, lipid parameters or body mass index. Subjects with a higher waist circumference at inclusion were at a higher risk of having micro-albuminuria at 6 years compared to those with a normal waist circumference. Logical regression analysis showed that waist circumference as a continuous value, or greater than 94 cm for males and 88 cm for females, were predictive factors for the incidence of micro-albuminuria, after adjustment for age, hypertension, ACE inhibitor usage, fibrinogen, and blood glucose level. Abdominal adiposity is thus linked in both sexes to the development of microalbuminuria, which underlines the importance of measuring waist circumference when assessing risk factors for renal lesions in non-diabetic hypertensives.

Use of HbA1c in predicting progression to diabetes in French men and women: data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR)

OBJECTIVE

Early identification of subjects at high risk for diabetes is essential, and random HbA(1c) (A1C) may be more practical than fasting plasma glucose (FPG). The predictive value of A1C, in comparison to FPG, is evaluated for 6-year incident diabetes.

RESEARCH DESIGN AND METHODS

From the French cohort study Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR), 1,383 men and 1,437 women, aged 30-65 years, were volunteers for a routine health check-up. Incident diabetes was defined by FPG >or=7.0 mmol/l or treatment by antidiabetic drugs. Multivariate logistic regression models were used to predict diabetes at 6 years. Receiver operating characteristic curves compared the predictive values of A1C and FPG.

RESULTS

At 6 years, 30 women (2.1%) and 60 men (4.3%) had developed diabetes. Diabetes risk increased exponentially with A1C in both sexes (P < 0.001). After stratifying on FPG, A1C predicted diabetes only in subjects with impaired fasting glucose (IFG) (FPG >or=6.10 mmol/l): the odds ratio (95% CI) for a 1% increase in A1C was 7.20 (3.00-17.00). In these subjects, an A1C of 5.9% gave an optimal sensitivity of 64% and specificity of 77% to predict diabetes.

CONCLUSIONS

A1C predicted diabetes, even though the diagnosis of diabetes was based on FPG, but it was less sensitive and specific than FPG. It could be used as a test if fasting blood sampling was not available or in association with FPG. In subjects with IFG, A1C is better than glucose to evaluate diabetes risk, and it could be used to select subjects for intensive early intervention.

The PPARG Pro12Ala polymorphism is associated with a decreased risk of developing hyperglycemia over 6 years and combines with the effect of the APM1 G-11391A single nucleotide polymorphism: the Data From an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) study

Although cross-sectional studies have associated the Pro12Ala polymorphism of PPARG with type 2 diabetes, prospective studies offer more opportunities to investigate genetic variants. Associations between PPARG polymorphisms with insulin resistance parameters and with the 6-year incidence of impaired fasting glucose or type 2 diabetes were tested in 3,914 French Caucasians from the DESIR (Data From an Epidemiological Study on the Insulin Resistance Syndrome) cohort. In subjects normoglycemic at baseline (n = 3,498), the 6-year risk of hyperglycemia was lower in PPARG Ala carriers (odds ratio [OR] vs. ProPro = 0.66 [95% CI 0.44-0.99], P = 0.046 adjusted for sex, age, and BMI). Similar results were found with the PPARG C1431T single nucleotide polymorphism (SNP; adjusted OR = 0.65 [0.44-0.96], P = 0.036). Both alleles are in strong linkage disequilibrium (D' = 0.669, P < 0.001). The baseline mean fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were lower in Ala carriers compared with ProPro homozygotes (P = 0.001 for both), with smaller increases in mean insulin and HOMA-IR during follow-up (P = 0.007 and 0.018, respectively). No association with insulin levels or HOMA-IR was found with C1431T. In this cohort, the APM1 G-11391A SNP is associated with the development of hyperglycemia. The combined effects of PPARG Pro12Ala and APM1 G-11391A SNPs showed no interaction on the risk of 6-year hyperglycemia. The PPARG Ala allele showed a relatively high protective effect in developing hyperglycemia and hyperinsulinemia during a 6-year period. Cumulative rather than synergistic effects of PPARG Pro12Ala and APM1 SNPs on diabetes risk are suggested.

α1-antitrypsin gene polymorphisms are not associated with renal arterial fibromuscular dysplasia

OBJECTIVE

We previously showed that fibromuscular dysplasia (FMD) of the renal artery may be familial. Case reports have associated alpha1-antitrypsin deficiency and FMD. The aim of this study was to test the implication of the alpha1-antitrypsin (AAT) gene in a large cohort of patients with renal FMD.

MATERIALS AND METHODS

A case-control study comparing the genotype frequencies in 161 consecutive patients with angiographically proven renal FMD with those observed in three sets of controls (353 hypertensive patients, 288 normotensive patients, 444 normotensive women) was conducted. High-resolution echotracking of the carotid and radial arteries was performed in a subset of 77 FMD patients. Three functional polymorphisms of the AAT gene (PiM1, PiZ, PiS) were investigated.

RESULTS

Clinical (age 44.3 +/- 13.8 years, 85.1% women) and radiological (77.1% of multifocal lesions) characteristics of the FMD population were consistent with those previously published. No differences were found in AAT genotype frequencies in the FMD subjects compared with the 1085 controls. We found no correlation between the AAT genotypes and the clinical and angiographical characteristics of the FMD patients. Echotracking results confirmed our previously published results in FMD patients with a specific pattern and a mean arterial phenotypic score greater than 3. However, no difference in the arterial score was observed across the genotypes.

CONCLUSION

Polymorphisms PiM1, PiZ and PiS of the AAT gene are not associated with renal FMD or infraclinical carotid lesions detected by echotracking methods. As the true prevalence of renal FMD is not precisely known and alpha1-antitrypsin deficiency is not infrequent in the general population, the association of the two may occur by chance.

Relations among night work, dietary habits, biological measure, and health status

A cross-sectional study was conducted to investigate dietary intake, behavioral habits, and clinical and metabolic differences in night workers compared to day workers and to evaluate the metabolic differences associated with diet and body habits that occur between these two groups. Dietary habits, biological parameters, and health status were collected in 1,200 night workers and in an equal number of day workers, matched for gender, age, and socioeconomic status. Our findings demonstrated that night workers had poorer dietary habits and metabolic profile compared to day workers with a similar overall health status. These differences were associated with a higher prevalence of some cardiovascular risk factors such as smoking and obesity.

Usefulness of the hepatitis C virus core antigen assay for screening of a population undergoing routine medical checkup

We studied the usefulness of the recently designed Trak-C assay for the detection and quantification of the hepatitis C virus (HCV) core antigen (Ag) for the screening of HCV infection in 4,201 subjects selected from 74,150 consecutive volunteers undergoing routine medical checkups. Subjects were selected for screening because they had risk factors (group II, n = 321) and/or elevated alanine transaminase activity (group I, n = 3847). Initially, the anti-HCV antibody assay and the Trak-C assay were performed on each patient. Subsequently, the Trak-C assay was performed only when the anti-HCV enzyme immune assay (EIA) was positive. Positive samples were further evaluated for anti-HCV antibodies by a third-generation strip immunoblot assay and for HCV RNA. Four samples (1.2%) from group II and 113 (2.9%) from group I were anti-HCV EIA positive. We also tested 33 subjects who previously tested positive for anti-HCV in our medical center. Among the 150 anti-HCV EIA-positive samples, the HCV core Ag result was in accord with the HCV RNA result in 146 cases (97.3%). When the EIA result was positive, the HCV core Ag concentration and the HCV RNA load were correlated (r(2) = 0.78; P < 0.001). Four samples with low viral loads were Trak-C negative but HCV RNA positive. Among the 2,395 anti-HCV EIA-negative serum samples collected during the first part of the study, 17 (0.7%) were found to contain very low levels of HCV core Ag (<8.5 pg/ml, the cutoff value being 1.5 pg/ml). All these samples were HCV RNA negative and considered to be false positives. This was confirmed by HCV core Ag neutralization analysis. The HCV core Ag assay is a useful method in the screening strategy of HCV infection and provides a reliable means of distinguishing between current and cleared HCV infections that is well correlated with HCV RNA testing.

Increased plasma adiponectin concentrations are associated with microangiopathy in type 1 diabetic subjects

AIMS/HYPOTHESIS

Insulin resistance is related to an increased risk of diabetic retinopathy and nephropathy in type 1 diabetes. Patients with insulin resistance and/or macrovascular disease have abnormally low levels of adiponectin. The aim of this study was to investigate the relationships between adiponectin and renal and retinal diabetic complications in type 1 diabetic patients.

METHODS

In this 6-year prospective follow-up observational study, we evaluated the severity of retinopathy at baseline and determined the incident risk of microalbuminuria in 126 normoalbuminuric patients with type 1 diabetes. Each patient was age- and sex-matched to two non-diabetic control subjects.

RESULTS

Plasma adiponectin concentrations were significantly higher in diabetic subjects than in control subjects (p < 0.0001). The adiponectin concentration was significantly higher in patients with severe diabetic retinopathy than in those without (39.1+/-14.0 vs 29.0+/-13.0 microg/ml, p = 0.0005). The 18 patients who developed persistent microalbuminuria had higher adiponectin concentrations than the other patients (35.8+/-14.5 vs 30.6+/-13.7 microg/ml). Increased adiponectin concentrations were independently associated with the occurrence of microalbuminuria (p = 0.0158) after adjustment for baseline urinary albumin concentration (p = 0.004), sex (p = 0.0054), blood pressure (NS) and metabolic control (NS).

CONCLUSIONS/INTERPRETATION

The elevated adiponectin concentrations observed in subjects with microvascular disease may indicate an altered regulation of this adipocytokine in patients with complications associated with type 1 diabetes.

Blood lipid and lipoprotein levels: relationships with educational level and region of residence in the French SU.VI.MAX study

BACKGROUND

Blood lipid profile of French men and women obtained from the general population is not well known. Furthermore, the association between these lipids, as a function of other potential risk factors for cardiovascular disease, and sociodemographic factors such as age, educational level, and region of residence is not well studied in large samples in Europe.

METHODS

Data on French healthy volunteers, aged between 40 and 65 years for men (n = 5141) and 35 and 65 years for women (n = 7876) were obtained from the "Supplementation en Vitamines et Mineraux Antioxydants" (SU.VI.MAX) study, a primary prevention trial. Baseline blood samples were collected in 1994-1995 and analyzed for cholesterol, triglyceride, apolipoproteins (apo)-B and -A1. The results were analyzed separately for men and women as a function of age, educational level, and area of residence.

RESULTS

Overall, blood lipid levels for men and women did not differ significantly from those reported in other Western industrialized countries. Except for triglyceride in men, all blood lipids were statistically different among ages. In women, cholesterol, apo-A1, and apo-B showed a significant decrease with educational level. Statistical differences were found in both genders between blood lipids and lipoproteins among regions of residence.

CONCLUSIONS

Even if differences between region of residence were found in blood lipid levels, this cannot explain the North-East to South gradient in the prevalence of cardiovascular disease in France nor differences between France and other industrialized Western countries.

Alterations of the lipid profile after 7.5 years of low-dose antioxidant supplementation in the SU.VI.MAX study

Antioxidant micronutrients have been reported to be associated with an improvement in the blood profile, but the results are not consistent. The aim of the present study was to assess the effects of antioxidant supplementation on changes in the serum lipid profile of adult participants in the SU.VI.MAX study. French adults (n = 12,741: 7,713 females aged 35-60 yr, and 5,028 males aged 45-60 yr) received daily antioxidant supplementation (120 mg vitamin C, 30 mg vitamin E, 6 mg beta-carotene, 100 microg selenium, and 20 mg zinc) or a matching placebo. Median follow-up time was 7.5 yr. After 7.5 yr, no effect of supplementation on total cholesterol was observed in men or women after adjusting for baseline total cholesterol levels and lipid-lowering medications. The prevalence of hypercholesterolemia (> or =6.5 mmol/L) showed a trend toward being higher in women who received supplements compared with those who received the placebo (P= 0.06). In both sexes, the group receiving supplements exhibited higher mean serum TG concentrations than did the placebo group (P= 0.06 in men; P= 0.05 in women). The prevalence of hypertriglyceridemia (> or =2.3 mmol/L) was also significantly higher in men who received supplements (P= 0.03), but not in women. Our results suggest than long-term daily supplementation with low doses of beta-carotene, vitamins C and E, selenium, and zinc does not result in an improved lipid profile and could even adversely affect some blood lipids, possibly with a higher risk of hyperlipidemia in women.

Polymorphisms of the Receptor of Advanced Glycation Endproducts (RAGE) and the development of nephropathy in type 1 diabetic patients

OBJECTIVES

We investigated the association of the RAGE (Receptor for Advanced Glycation End products) exon3 gene polymorphisms with stages of nephropathy in type 1 diabetes.

METHODS

The RAGE exon 3 genotype was assessed by Denaturing Gradient Gel Electrophoresis (DGGE) procedure in 487 type 1 diabetic patients with proliferative retinopathy subdivided into four groups according to their level of renal involvement and in 351 control subjects (GENEDIAB study).

RESULTS

We reported here three main low frequency dimorphisms, previously submitted to data banks, Gly82Ser, Val89 CTC/CTG, and Arg77Cys. The genotype distribution of these polymorphisms was not statistically different in type 1 diabetic patients compared to healthy controls (p=0.37). Among the three described polymorphisms, only the RAGE Gly82Ser genotype frequency was significantly increased in the group with advanced nephropathy (11%) defined by a chronic renal failure compared to the three others groups: no nephropathy, 5%; incipient (microalbuminuria) 5%; established (macroalbuminuria), 2%) (P=0.04). The 82 Ser allele was identified as an independent risk marker for the stage of advanced nephropathy: adjusted odds ratio 3.17(95% CI 1,32-7,85, p=0.008).

CONCLUSION

These data suggest that the 82 Ser allele of the RAGE gene is a risk allele for developing advanced nephropathy. This suggests that some RAGE gene polymorphisms may be associated with progression to diabetic advanced nephropathy in Caucasian type 1 diabetic patients.

Cigarette smoking and diabetes mellitus

OBJECTIVE

To assess whether an independent relationship between cigarette smoking and type 2 diabetes exists in both men and women selected from a French population, and to assess the effects of active smoking and smoking cessation on the prevalence of diabetes.

METHODS

A population-based cross sectional study in 28,409 volunteers.

RESULTS

After adjustment for age, BMI, waist-hip ratio (WHR) and alcohol, the risk of diabetes mellitus (estimated by the odds ratio) was 1.49 (1.13-1.96, P=0.004) and 1.31 (1.01-1.17, P=0.03) for current and former smoker men, respectively, as compared to non-smoker men. The risk was even higher in men aged 40 to 69. No association was found with the duration of smoking cessation. In women, the risk of diabetes associated with current smoking was much less significant [HR: 1.46 (0.92-2.22, P=0.09)], even in women aged 40 to 69 [HR: 1.60 (1.00-2.58, P=0.05)]. No relationship was found for past smoking in women. In non-diabetic men, the adjusted fasting glucose was similar in current and in non smokers, but it was higher in current smokers aged 40 to 69 (99.2 +/- 0.27 vs 98.7 +/- 0.14 mg/dl, P=0.05). It was higher in former than in non smokers (97.4 +/- 0.20 vs 96.0 +/- 0.10 mg/dl, P=0.0001), regardless of age. In non-diabetic women, the adjusted fasting glucose was lower in current than in non smokers (90.7 +/- 0.20 vs 91.4 +/- 0.12 mg/dl, P=0.0001), even in women aged 40 to 69 (93.0 +/- 0.35 vs 93.7 +/- 0.18 mg/dl, P=0.03). It was similar in former and in non smokers, regardless of the age.

CONCLUSIONS

Current and past smoking are associated with a risk of diabetes mellitus essentially in men, but much less in women, and the relationship between fasting glucose and smoking appears different in men and women. No dose-relationship between the number of cigarettes smoked and diabetes mellitus was found. Smoking cessation is not associated with a reduced risk of diabetes.

Adiponectin gene polymorphisms and adiponectin levels are independently associated with the development of hyperglycemia during a 3-year period: the epidemiologic data on the insulin resistance syndrome prospective study

The plasma concentration of the adipocyte-derived peptide adiponectin is decreased in patients with obesity and type 2 diabetes. The adiponectin gene is located on chromosome 3q27, where a diabetes susceptibility locus has been mapped. Adiponectin gene polymorphisms (single nucleotide polymorphisms [SNPs]) have been associated with BMI, insulin sensitivity, and type 2 diabetes in some cross-sectional studies. Our aim was to assess the contribution of these SNPs in the development of features of the insulin resistance syndrome in a 3-year prospective study in approximately 4,500 French Caucasian subjects from the Epidemiologic Data on the Insulin Resistance Syndrome (DESIR) cohort. For subjects who were normoglycemic at baseline, the 3-year risk of becoming hyperglycemic (diabetes or impaired fasting glucose) was affected by two SNPs: G-11391A and T45G. For G-11391A, the risk was increased in GA carriers (odds ratio [OR] adjusted for sex [versus GG] = 1.60 [95% CI 1.16-2.20]; P = 0.004). For T45G, it was increased in GG carriers (OR [versus TT] = 2.71 [1.31-5.60]; P = 0.007). After 3 years, GG subjects had a greater increase in BMI (P = 0.009) and waist-to-hip ratio (P = 0.007). Adiponectin levels at baseline were associated with the development of hyperglycemia (P = 0.005), but the predictive effects on the risk for hyperglycemia were independent of adiponectin genotypes. In conclusion, in the DESIR study, variations at the adiponectin locus affect body weight gain, body fat distribution, and onset of hyperglycemia, as well as adiponectin levels. Adiponectin gene SNPs may have several phenotypic effects that co-occur with the development of the metabolic syndrome.

Comparison of men with impaired fasting glycaemia to controls and to diabetic subjects with fasting glycaemia from 7.0 to 7.7 mmol/l: clinical, nutritional and biological status

OBJECTIVE

To compare medical history, clinical, nutritional and biological status of non-diabetic men to subjects with impaired fasting glycemia (glycemia 6.1-6.9 mmol/l) and to newly diagnosed type 2 diabetic subjects (7.0-7.7 mmol/l) according to the criteria proposed by the American Diabetes Association.

METHODS

Cross-sectional study of a cohort of 29,992 men, who were volunteers for a free periodic check-up offered by their medical insurance. Medical history, lifestyle and nutritional habits were recorded using a self-administered questionnaire. Clinical and biological data were also studied. To compare the three groups of subjects - normal, impaired fasting glycemia and newly diagnosed diabetics - three age stratified samples were randomly designed.

RESULTS

Most of the well-known risk factors for developing type 2 diabetes mellitus such as overweight, abdominal obesity, familial history of diabetes mellitus, over-consumption of fat and alcohol were present in the group with impaired fasting glycaemia which presented the same risk factors as the group of subjects with fasting glycaemia from 7.0 to 7.7 mmol/l, but to a lesser degree. Hypertension was present in more than 50% of the subjects with impaired fasting glycaemia.

CONCLUSION

In this cross-sectional study, impaired fasting glycaemia is associated with the risk factors of type 2 diabetes mellitus. The subjects with impaired fasting glycaemia should be considered at risk for cardiovascular disease and might take advantage from early specific intervention about their lifestyle.

The incidence and persistence of the NCEP (National Cholesterol Education Program) metabolic syndrome. The French D.E.S.I.R. study

CONTEXT

In 2001 the "National Cholesterol and Education Program Expert Panel" gave a clinical definition of the metabolic syndrome. The frequency of this syndrome at baseline and its incidence and persistence at three years is studied in a French population.

SUBJECTS

2109 men and 2184 women from the D.E.S.I.R. longitudinal cohort study (Data from an Epidemiological Study on the Insulin Resistance syndrome) in central-western France, aged 30 to 64 years, were examined at inclusion and three years later.

METHODS

Evaluation of the frequencies, incidences and persistence of the metabolic syndrome and its abnormalities. This syndrome is defined by the presence of three or more of five abnormalities: waist circumference > 102/88 cm (men/women); triglycerides > o r=1.69 mmol/l, HDL-cholesterol<1.04/1.29 mmol/l (men/women); systolic/diastolic blood pressure > or =130 and/or 85 mmHg; fasting plasma glucose > or =6.1 mmol/l.

RESULTS

At baseline, 10% of men and 7% of women had the metabolic syndrome. If the syndrome was defined to include a treatment in the abnormalities (for diabetes, hypertension, dyslipidemia), the syndrome frequencies increased to 16% and 11%. However only 12% and 8% respectively, had this syndrome both at inclusion and at three years. High blood pressure was the most frequent abnormality: 70% and 47% in men and women respectively, at inclusion. The most stable abnormality was high waist circumference (80% persisted), hyperglycaemia the least stable (60% persisted). Hyperinsulinaemia did not cluster closely with this syndrome.

CONCLUSIONS

The age-specific frequency of the syndrome is more than 2.5 times higher in the US than in this French cohort and this ratio increased with age. The higher frequencies of abdominal obesity and low HDL-cholesterol in women than in men suggest that these gender-specific thresholds may need to be refined.