Associations between blood glucose and carotid intima-media thickness disappear after adjustment for shared risk factors: the KORA F4 study.

The association between blood glucose and carotid intima-media thickness (CIMT) is considered to be established knowledge. We aimed to assess whether associations between different measures of glycaemia and CIMT are actually independent of anthropometric variables and metabolic risk factors. Moreover, we checked published studies for the adjustment for shared risk factors of blood glucose and CIMT. Fasting glucose, 2-hour glucose, HbA1c, and CIMT were measured in 31-81-years-old participants of the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4 study in Southern Germany (n = 2,663). CIMT was assessed according to the Rotterdam protocol. Linear and logistic regression models with adjustment for age, sex, anthropometric measures, hypertension, and dyslipidaemia were fitted to assess the association between continuous measures of glycaemia, and categories of glucose regulation, respectively, with CIMT. We found a 0.10 mm increase (95%-confidence interval: 0.08-0.12) in CIMT in subjects with compared to subjects without diabetes in crude analysis. This increase was not significant in age-sex adjusted models (p = 0.17). Likewise, neither impaired fasting glucose (p = 0.22) nor impaired glucose tolerance (p = 0.93) were associated with CIMT after adjustment for age, sex, and waist circumference. In multivariable adjusted models, age, sex, hypertension, waist circumference, HDL and LDL cholesterol, but neither fasting glucose nor 2-hour glucose nor HbA1c were associated with elevated CIMT. Literature findings are inconclusive regarding an independent association of glucose levels and CIMT. CIMT is highly dependent on traditional cardiovascular risk factors, but no relationships between blood glucose and CIMT were found after adjustment for age, sex, and anthropometric variables

Uric acid is more strongly associated with impaired glucose regulation in women than in men from the general population: the KORA F4-Study.

High serum uric acid (UA) levels are associated with the metabolic syndrome, type 2 diabetes and cardiovascular disease. It is largely unknown whether there are gender-specific differences regarding the association between UA and prediabetic states. We examined the possible association between UA levels and known as well as newly diagnosed diabetes (NDD), isolated impaired fasting glucose (i-IFG), isolated impaired glucose tolerance (i-IGT), and combined IFG/IGT in a population-based sample of 32-to-81-year-old men and women. An oral glucose tolerance test was carried out in all 2,740 participants without known diabetes of the Cooperative Health Research in the Region of Augsburg (KORA) F4 Study conducted between 2006 and 2008 in Southern Germany. Serum UA was analysed by the uricase method. In women after multivariable adjustment the associations between UA and i-IFG (OR 1.57, 95% CI 1.15-2.14), IFG/IGT (OR 1.52, 1.07-2.16), NDD (OR 1.67, 95% CI 1.28-2.17), and known diabetes (OR 1.47, 95% CI 1.18-1.82) remained significant, but the association with i-IGT (OR 1.14, 95% CI 0.95-1.36) lost significance. In contrast in men, after multivariable adjustment there was only a significant association between UA levels and i-IFG (OR 1.49, 95% CI 1.21-1.84), all other associations were non-significant (i-IGT: OR 1.09, IFG/IGT: OR 1.06, NDD: OR 0.91, known diabetes: OR 1.04; all p-values>0.05). Serum UA concentrations were associated with different categories of impaired glucose regulation in individuals from the general population, particularly in women. Further studies investigating the role of UA in the development of derangements in glucose metabolism are needed

Age at menarche and its association with the metabolic syndrome and its components

The metabolic syndrome is a major public health challenge and identifies persons at risk for diabetes and cardiovascular disease. The aim of this study was to examine the association between age at menarche and the metabolic syndrome (IDF and NCEP ATP III classification) and its components. 1536 women aged 32 to 81 years of the German population based KORA F4 study were investigated. Data was collected by standardized interviews, physical examinations, and whole blood and serum measurements. Young age at menarche was significantly associated with elevated body mass index (BMI), greater waist circumference, higher fasting glucose levels, and 2 hour glucose (oral glucose tolerance test), even after adjusting for the difference between current BMI and BMI at age 25. The significant effect on elevated triglycerides and systolic blood pressure was attenuated after adjustment for the BMI change. Age at menarche was inversely associated with the metabolic syndrome adjusting for age (p-values: <0.001 IDF, 0.003 NCEP classification) and additional potential confounders including lifestyle and reproductive history factors (p-values: 0.001, 0.005). Associations remain significant when additionally controlling for recollected BMI at age 25 (p-values: 0.008, 0.033) or the BMI change since age 25 (p-values: 0.005, 0.022). Young age at menarche might play a role in the development of the metabolic syndrome. This association is only partially mediated by weight gain and increased BMI. A history of early menarche may help to identify women at risk for the metabolic syndrome

Gene-Gene Interaction between APOA5 and USF1: Two Candidate Genes for the Metabolic Syndrome

Objective: The metabolic syndrome, a major cluster of risk factors for cardiovascular diseases, shows increasing prevalence worldwide. Several studies have established associations of both apolipoprotein A5 (APOA5) gene variants and upstream stimulatory factor 1 (USF1) gene variants with blood lipid levels and metabolic syndrome. USF1 is a transcription factor for APOA5. Methods: We investigated a possible interaction between these two genes on the risk for the metabolic syndrome, using data from the German population-based KORA survey 4 (1,622 men and women aged 55-74 years). Seven APOA5 single nucleotide polymorphisms (SNPs) were analyzed in combination with six USF1 SNPs, applying logistic regression in an additive model adjusting for age and sex and the definition for metabolic syndrome from the National Cholesterol Education Program's Adult Treatment Panel III (NCEP (AIII)) including medication. Results: The overall prevalence for metabolic syndrome was 41%. Two SNP combinations showed a nominal gene-gene interaction (p values 0.024 and 0.047). The effect of one SNP was modified by the other SNP, with a lower risk for the metabolic syndrome with odds ratios (ORs) between 0.33 (95% CI = 0.13-0.83) and 0.40 (95% CI = 0.15-1.12) when the other SNP was homozygous for the minor allele. Nevertheless, none of the associations remained significant after correction for multiple testing. Conclusion: Thus, there is an indication of an interaction between APOA5 and USF1 on the risk for metabolic syndrome

Association of faecal elastase 1 with non-fasting triglycerides in type 2 diabetes.

AIMS: Intestinal absorption of esterified fatty acids depends on exocrine pancreatic function and influences plasma triglycerides levels. The aim was to investigate the association of reduced exocrine pancreatic function (low fecal elastase-1; FE1) with plasma triglycerides in type 2 diabetes and controls without diabetes. METHODS: FE1 (μg/g stool) and non-fasting plasma triglyceride measurements were undertaken in 544 type 2 diabetes patients (age: 63 ± 8 years) randomly selected from diabetes registers in Cambridgeshire (UK), and 544 matched controls (age, sex, practice) without diabetes. Linear regression models were fitted using FE1 as dependent and log-triglycerides as independent variable adjusting for sex, age, body mass index, alcohol consumption, serum lipase, HbA1c, and smoking. RESULTS: FE1 concentrations were lower (mean ± SD: 337 ± 204 vs. 437 ± 216 μg/g, p < 0.05) and plasma triglycerides were higher (geometric mean */: standard deviation factor: 2.2*/:1.9 vs. 1.6*/:1.8 mmol/l, p < 0.05) in type 2 diabetes compared to controls, respectively. Within the category of type 2 diabetes and controls separately, a 10% increase in plasma triglycerides was associated with 4.5 μg/g higher FE1 concentrations (p < 0.01) after adjusting for confounders. In contrast, in diabetes patients and controls with pathological FE1 (<100 μg/g), low FE1 levels were associated with high plasma triglycerides (significant only in controls). CONCLUSIONS: Non-fasting triglycerides were positively related to FE1 in both type 2 diabetes and controls suggesting that impairment of exocrine pancreas function is influencing plasma triglycerides. Marked loss of exocrine pancreatic function had the opposite effect, resulting in higher levels of plasma triglycerides.The analysis of the Cambridgeshire study was supported by an unrestricted grant from AstraZeneca, Sweden.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.pan.2016.03.01

Association between Markers of Fatty Liver Disease and Impaired Glucose Regulation in Men and Women from the General Population: The KORA-F4-Study

OBJECTIVE: To investigate whether the elevated liver enzymes gamma-glutamyltransferase (GGT), glutamate-pyruvate transaminase (GPT), glutamate-oxalacetate transaminase (GOT) and alkaline phosphatase (AP) and non-alcoholic fatty liver disease (NAFLD) respectively are independently associated with pre-diabetic states, namely impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) or known and newly diagnosed diabetes (NDD), in men and women from the general German population. METHODS: The study was based on 3009 subjects (1556 females, 1453 males) aged 32 to 81 years who participated in the KORA-F4-Study in 2006/2008 in Augsburg, Southern Germany. All non-diabetic participants underwent an oral glucose tolerance test to assess disturbances in glucose metabolism. NAFLD was estimated by liver enzyme concentrations and the Bedogni Fatty Liver Index (FLI). RESULTS: 229 participants (7.6%) reported known diabetes, 106 had NDD (3.5%), 107 (3.6%) had IFG, 309 (10.3%) had IGT, 69 (2.3%) were affected with both metabolic disorders (IFG/IGT) and 74 (2.5%) could not be classified. GGT and GPT were significantly elevated in persons with pre-diabetes and diabetes (GGT in diabetic persons OR = 1.76, [1.47-2.09], in IFG OR = 1.79 [1.50-2.13], GPT in diabetic persons OR = 1.51, [1.30-1.74], in NDD OR = 1.77 [1.52-2.06]), GOT and AP only inconsistently in some pre-diabetes groups. The effects were sharpened in models using an increase of two or three out of three enzymes as an estimate of fatty liver and especially in models using the FLI. Overall frequency of NAFLD applying the index was 39.8% (women: 27.3% and men: 53.2%). In participants with fatty liver disease, the OR for NDD adjusted for sex and age was 8.48 [5.13-14.00], 6.70 [3.74-12.01] for combined IFG and IGT and 4.78 [3.47-6.59] for known diabetes respectively. CONCLUSIONS: Elevated GGT and GPT-values as well as estimates of fatty liver disease are significantly associated with pre-diabetes and diabetes and thus very useful first indicators of a disturbed glucose metabolism

Serum levels of interleukin-22, cardiometabolic risk factors and incident type 2 diabetes: KORA F4/FF4 study

AIMS: Interleukin-22 (IL-22) has beneficial effects on body weight, insulin resistance and inflammation in different mouse models, but its relevance for the development of type 2 diabetes in humans is unknown. We aimed to identify correlates of serum IL-22 levels and to test the hypothesis that higher IL-22 levels are associated with lower diabetes incidence. METHODS: Cross-sectional associations between serum IL-22, cardiometabolic risk factors and glucose tolerance status were investigated in 1107 persons of the population-based KORA F4 study. The prospective association between serum IL-22 and incident type 2 diabetes was assessed in 504 initially non-diabetic study participants in both the KORA F4 study and its 7-year follow-up examination KORA FF4, 76 of whom developed diabetes. RESULTS: Male sex, current smoking, lower HDL cholesterol, lower estimated glomerular filtration rate and higher serum interleukin-1 receptor antagonist were associated with higher IL-22 levels after adjustment for confounders (all P &lt; 0.05). Serum IL-22 showed no associations with glucose tolerance status, prediabetes or type 2 diabetes. Baseline serum IL-22 levels (median, 25th/75th percentiles) for incident type 2 diabetes cases and non-cases were 6.28 (1.95; 12.35) and 6.45 (1.95; 11.80) pg/ml, respectively (age and sex-adjusted P = 0.744). The age and sex-adjusted OR (95% CI) per doubling of IL-22 for incident type 2 diabetes of 1.02 (0.85; 1.23) was almost unchanged after consideration of further confounders. CONCLUSIONS: High serum levels of IL-22 were positively rather than inversely associated with several cardiometabolic risk factors. However, these associations did not translate into an increased risk for type 2 diabetes. Thus, our data argue against the utility of IL-22 as biomarker for prevalent or incident type 2 diabetes in humans, but identify potential determinants of IL-22 levels which merits further research in the context of cardiovascular diseases

Optimized metabotype definition based on a limited number of standard clinical parameters in the population-based KORA study

The aim of metabotyping is to categorize individuals into metabolically similar groups. Earlier studies that explored metabotyping used numerous parameters, which made it less transferable to apply. Therefore, this study aimed to identify metabotypes based on a set of standard laboratory parameters that are regularly determined in clinical practice. K-means cluster analysis was used to group 3001 adults from the KORA F4 cohort into three clusters. We identified the clustering parameters through variable importance methods, without including any specific disease endpoint. Several unique combinations of selected parameters were used to create different metabotype models. Metabotype models were then described and evaluated, based on various metabolic parameters and on the incidence of cardiometabolic diseases. As a result, two optimal models were identified: a model composed of five parameters, which were fasting glucose, HDLc, non-HDLc, uric acid, and BMI (the metabolic disease model) for clustering; and a model that included four parameters, which were fasting glucose, HDLc, non-HDLc, and triglycerides (the cardiovascular disease model). These identified metabotypes are based on a few common parameters that are measured in everyday clinical practice. These metabotypes are cost-effective, and can be easily applied on a large scale in order to identify specific risk groups that can benefit most from measures to prevent cardiometabolic diseases, such as dietary recommendations and lifestyle interventions

The effect of retirement on biomedical and behavioral risk factors for cardiovascular and metabolic disease

Retirement is a major life event potentially associated with changes in relevant risk factors for cardiovascular and metabolic conditions. This study analyzes the effect of retirement on behavioral and biomedical risk factors for chronic disease, together with subjective health parameters using Southern German epidemiological data. We used panel data from the KORA cohort study, consisting of 11,168 observations for individuals 45–80 years old. Outcomes included health behavior (alcohol, smoking, physical activity), biomedical risk factors (BMI, waist-to-hip ratio (WHR), glycosylated hemoglobin (HbA1c), total cholesterol/HDL quotient, systolic/diastolic blood pressure), and subjective health (SF12 mental and physical, self-rated health). We applied a parametric regression discontinuity design based on age thresholds for pension eligibility. Robust results after p-value corrections for multiple testing showed an increase in BMI in early retirees (at the age of 60) [β = 1.11, corrected p-val. &lt; 0.05] and an increase in CHO/HDL in regular retirees (age 65) [β = 0.47, corrected p-val. &lt; 0.05]. Stratified analyses indicate that the increase in BMI might be driven by women and low-educated individuals retiring early, despite increases in the level of physical activity. The increase in CHO/HDL might be driven by men retiring regularly, alongside an increase in subjective physical health. Blood pressure also increased, but the effect differs by retirement timing and sex and is not always robust to sensitivity analysis checks. Our study indicates that retirement has an impact on different risk factors for chronic disease, depending on timing, gender and education. Regular male, early female, and low-educated retirees should be further investigated as potential high-risk groups for worsening risk factors after retirement. Future research should investigate if and how these results are linked: in fact, especially in the last two groups, the increases in leisure time physical activity might not be enough to compensate for the loss of work related physical activity, leading thus to an increase in BMI