Time spent on self-management by people with diabetes: results from the population-based KORA survey in Germany.

AIMS: Time needed for health-related activities in people with diabetes is assumed to be substantial, yet available data are limited. Time spent on self-management and associated factors was analysed using cross-sectional data from people with diagnosed diabetes enrolled in a population-based study. METHODS: Mean total time spent on self-management activities was estimated using a questionnaire for all participants with diagnosed diabetes in the KORA FF4 study (n = 227, 57% men, mean age 69.7, sd 9.9 years). Multiple two-part regression models were fitted to evaluate associated factors. Multiple imputation was performed to adjust for bias due to missing values. RESULTS: Some 86% of participants reported spending time on self-management activities during the past week. Over the entire sample, a mean of 149 (sd 241) min/week were spent on self-management-activities. People with insulin or oral anti-hyperglycaemic drug treatment, better diabetes education, HbA1c 48 to < 58 mmol/mol (6.5% to < 7.5%) or lower quality of life, spent more time on self-management activities. For example, people without anti-hyperglycaemic medication invested 66 min/week in self-management, whereas those taking insulin and oral anti-hyperglycaemic drugs invested 269 min/week (adjusted ratio 4.34, 95% confidence interval 1.85-10.18). CONCLUSIONS: Time spent on self-management activities by people with diabetes was substantial and varied with an individual's characteristics. Because of the small sample size and missing values, the results should be interpreted in an explorative manner. Nevertheless, time needed for self-management activities should be routinely considered because it may affect diabetes self-care and quality of life.

Prediabetes is associated with microalbuminuria, reduced kidney function and chronic kidney disease in the general population: The KORA (Cooperative Health Research in the Augsburg Region) F4-Study.

BACKGROUND AND AIMS: We investigated the associations of serum fasting (FG) and 2-h postload (2HG) glucose from an oral glucose tolerance test (OGTT), glycated hemoglobin (HbA1c), fasting insulin and the homeostasis model assessment-insulin resistance index (HOMA-IR) with urinary albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR). METHODS AND RESULTS: We performed cross-sectional analyses of 2713 subjects (1429 women; 52.7%) without known type 2 diabetes, aged 31-82 years, from the KORA (Cooperative Health Research in the Augsburg Region) F4-Study. FG, 2HG, HbA1c, fasting insulin, HOMA-IR and glucose tolerance categories were analyzed for association with ACR and eGFR in multivariable adjusted linear and median regression models, and with isolated microalbuminuria (i-MA), isolated reduced kidney function (i-RKF) and chronic kidney disease (CKD, defined as MA and/or RKF) in multivariable adjusted logistic regression models. Among the 2713 study participants, 28% revealed prediabetes (isolated impaired fasting glucose [i-IFG], isolated glucose tolerance [i-IGT] or both by American Diabetes Association definition), 4.2% had unknown type 2 diabetes, 6.5% had i-MA, 3.1% i-RKF and 10.9% CKD. In multivariable adjusted analysis, all continuous variables (FG, 2HG, HbA1c, fasting insulin and HOMA-IR) were associated with i-MA, i-RKF and CKD. The odds ratios (ORs) for i-MA and CKD were 1.54 (95% confidence interval: 1.02-2.33) and 1.58 (1.10-2.25) for individuals with i-IFG. Moreover, the OR for i-RKF was 2.57 (1.31-5.06) for individuals with IFG + IGT. CONCLUSION: Our findings suggest that prediabetes might have harmful effects on the kidney.

Physical activity, muscular strength, and polypharmacy among older multimorbid persons: Results from the KORA-Age study.

The purpose of this study was to examine whether physical activity (PA) and muscular strength (MS) are related to polypharmacy. Our cross-sectional analysis was based on 711 patients with multimorbidity (MMB), aged 65-94 years, who participated in the KORA-Age study. Participants underwent a face-to-face interview and extensive physical examinations including anthropometric measurements, registration of chronic diseases, determination of health-related behaviors (smoking, alcohol intake, physical activity, etc.), collection of blood samples and measurement of hand-grip strength. PPha was defined as the use of >4 drugs and MMB as having ≥2 of 13 chronic diseases. Prevalence of PPha was 44.6% (n=317), and a significant difference was found in the number of drugs used between participants with and without PPha (7.2±2.1 vs 2.5±1.2, P<.001). Patients in the lower compared to the upper tertile of physical activity had a significantly increased odds to be on PPha (OR: 1.64, 95% CI: 1.05-2.56, P=.031) after controlling for age, gender, BMI, family status, education, alcohol intake, smoking habits, number of diseases, hs-CRP, and telomere length. On the contrary, no significant association between muscular strength and PPha was found (OR: 1.04, 95% CI: 0.66-1.63, P=.873) after multivariable adjustment. Among older persons with MMB, lower levels of physical activity, but not low muscular strength, are associated with higher odds of PPha. Increasing the levels of physical activity appears to be highly recommended in order to potentially reduce the risk of PPha among multimorbid persons aged 65 and older.

Life satisfaction is a protective factor against the onset of Type 2 diabetes in men but not in women: findings from the MONICA/KORA cohort study.

AIMS: To investigate the association of high life satisfaction with incident Type 2 diabetes separately in men and women. METHODS: A longitudinal analysis was conducted among the 7107 participants (3664 men, 51.5%; 3443 women, 48.5%) aged 25-74 years (mean ± sd age 47.8 ±13.7 years) of two population-based MONICA/KORA surveys conducted in 1989-1995 and followed up until 2009. Life satisfaction was assessed using a one-item instrument with a six-order response level, which was dichotomized into high vs medium or low. Sex-specific hazard ratios were estimated using Cox proportional hazards models. RESULTS: Crude incidence rates for Type 2 diabetes per 10 000 person-years were lower in participants with high than in those with medium or low life satisfaction (men: 57 vs 73; women: 37 vs 48). In men with high life satisfaction, there was a 27% risk reduction in incident Type 2 diabetes (hazard ratio 0.73, 95% CI 0.56-0.94; P=0.02) in a model adjusted for sociodemographic, behavioural and clinical risk factors. The association lost statistical significance after further adjusting for depressed mood (hazard ratio 0.79, 95% CI 0.61-1.03). Life satisfaction was not significantly associated with incident Type 2 diabetes in women. CONCLUSION: Life satisfaction may be a valuable asset in assessing risk of Type 2 diabetes, especially in men, and in the development of more effective prevention strategies to deter onset of diabetes. More research is needed to investigate the underlying potential causal pathways that may link life satisfaction to the development of Type 2 diabetes.

Sarcopenia is associated with disability status-results from the KORA-Age study.

We estimated the prevalence of sarcopenia and its impact on disability in older people. Sarcopenia was found to contribute to higher disability scores. However, our study was not able to show any influence of sarcopenia on the rate of functional decline. This directs attention to an accurate diagnosis of sarcopenia as the onset may be influenced, but its rate may not. INTRODUCTION: The objectives of this study using data from a population-based cohort were to estimate the prevalence of sarcopenia in older people in Germany and to test the hypothesis that sarcopenia is associated with disability in older adults. METHODS: Cross-sectional (n = 927) and longitudinal analyses (n = 859) of participants aged ≥65 years at baseline from southern Germany enrolled in the Cooperative Health Research in the Region Augsburg (KORA)-Age study (2009-2012). Sarcopenia was defined based on the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm which includes the presence of both low muscle mass and low muscle function (strength or performance). Disability status was measured by the Health Assessment Questionnaire-Disability Index (HAQ-DI). The presence of disability was defined as HAQ-DI >0. Directed acyclic graphs (DAGs) were constructed to identify potential confounders. The effect of sarcopenia on disability was analyzed using linear mixed effect models with disability values as a continuous outcome. RESULTS: The overall prevalence of sarcopenia was 5.7% (men 4.0%, women 7.5%) and increased with age. The 3-year incidence of disability was 32.7%. After adjustment for potential confounders, presence of sarcopenia was significantly associated with higher disability scores (0.142 [confidence interval 0.029-0.254]). CONCLUSION: The prevalence of sarcopenia is consistent with estimates from other European studies using this algorithm. Our results suggest that sarcopenia can contribute to higher disability scores in older adults. However, our study was not able to show any influence of sarcopenia on the rate of functional decline using the EWGSOP diagnostic algorithm for sarcopenia. This directs attention to an accurate diagnosis of sarcopenia as the onset may be influenced, but its rate may not.

Handgrip strength is inversely and independently associated with multimorbidity among older women: Results from the KORA-Age study.

BACKGROUND: Data on the association between handgrip strength and multimorbidity (MMB) are missing. AIM: The purpose of this study was to examine if handgrip strength is related to MMB in a large population-based sample of older persons. METHODS: The cross-sectional analysis was based on 1079 older people (aged 65-94years), who participated in the KORA-Age study in the Augsburg region, southern Germany. Participants underwent an interview and extensive examinations, including anthropometric measurements, registration of chronic diseases, determination of health-related behaviors (smoking, alcohol intake and physical activity), collection of blood samples, and muscle strength measurement using hand-grip dynamometry. RESULTS: In men, handgrip strength correlated strongly with the number of co-existing diseases (r=-0.176, p<0.001), and the same pattern was observed for women (r=-0.287, p<0.001). Among women, handgrip strength in the lower tertile compared to the upper tertile was significantly associated with an increased odds of having MMB (OR: 2.57, 95% CI: 1.30-5.07, p=0.007) after controlling for age, BMI, education, alcohol intake, smoking habits, medications number, inflammatory markers, telomere length and levels of physical activity. Contrary, no significant association between handgrip strength and MMB was found among men (OR: 1.32, 95% CI: 0.73-2.40, p=0.362) after multivariable adjustment. CONCLUSION: Lower levels of handgrip strength are associated with a higher odd of MMB among older women even after adjusting for traditional and novel confounders. Increasing the levels of muscular strength in older women seems to be important in order to reduce the risk for the co-occurrence of multiple chronic diseases.

HbA1c levels in non-diabetic older adults - No J-shaped associations with primary cardiovascular events, cardiovascular and all-cause mortality after adjustment for confounders in a meta-analysis of individual participant data from six cohort studies.

BACKGROUND: To determine the shape of the associations of HbA1c with mortality and cardiovascular outcomes in non-diabetic individuals and explore potential explanations. METHODS: The associations of HbA1c with all-cause mortality, cardiovascular mortality and primary cardiovascular events (myocardial infarction or stroke) were assessed in non-diabetic subjects ≥50 years from six population-based cohort studies from Europe and the USA and meta-analyzed. Very low, low, intermediate and increased HbA1c were defined as <5.0, 5.0 to <5.5, 5.5 to <6.0 and 6.0 to <6.5% (equals <31, 31 to <37, 37 to <42 and 42 to <48 mmol/mol), respectively, and low HbA1c was used as reference in Cox proportional hazards models. RESULTS: Overall, 6,769 of 28,681 study participants died during a mean follow-up of 10.7 years, of whom 2,648 died of cardiovascular disease. Furthermore, 2,493 experienced a primary cardiovascular event. A linear association with primary cardiovascular events was observed. Adjustment for cardiovascular risk factors explained about 50% of the excess risk and attenuated hazard ratios (95 confidence interval) for increased HbA1c to 1.14 (1.03-1.27), 1.17 (1.00-1.37) and 1.19 (1.04-1.37) for all-cause mortality, cardiovascular mortality and cardiovascular events, respectively. The six cohorts yielded inconsistent results for the association of very low HbA1c levels with the mortality outcomes and the pooled effect estimates were not statistically significant. In one cohort with a pronounced J-shaped association of HbA1c levels with all-cause and cardiovascular mortality (NHANES), the following confounders of the association of very low HbA1c levels with mortality outcomes were identified: race/ethnicity; alcohol consumption; BMI; as well as biomarkers of iron deficiency anemia and liver function. Associations for very low HbA1c levels lost statistical significance in this cohort after adjusting for these confounders. CONCLUSIONS: A linear association of HbA1c levels with primary cardiovascular events was observed. For cardiovascular and all-cause mortality, the observed small effect sizes at both the lower and upper end of HbA1c distribution do not support the notion of a J-shaped association of HbA1c levels because a certain degree of residual confounding needs to be considered in the interpretation of the results.

Changes in body weight and obesity status in German adults: results of seven population-based prospective studies.

BACKGROUND/OBJECTIVES: The objective of this study was to quantify body weight changes in German adult populations during the past decades. SUBJECTS/METHODS: Longitudinal analysis of seven cohort studies covering different age ranges between 18 and 83 years. Baseline examinations were between 1994 and 2007 and follow-up durations between 4.0 and 11.9 years. For each study, mean change in body weight per year and 10-year change in body mass index (BMI) classification were analyzed. For the middle age group of 45-64 years, meta-analysis was conducted to obtain an overall estimate for Germany. RESULTS: Among men weight gain was highest in the youngest participants and decreased with advancing age. Among women weight gain was on a stable high level among those younger than 45 years and decreased at older age. Within 10 years, 30-40% of middle-aged participants with normal baseline weight became pre-obese or obese and 20-25% of those with pre-obesity at baseline became obese, whereas >80% of persons who were obese at baseline remained obese over time. The estimated average weight change in adults aged 45-64 years was 0.25 (95% confidence interval (CI): 0.18-0.33) kg/year among men and 0.24 (0.17-0.30) kg/year among women. CONCLUSIONS: We could observe a moderate weight gain over the past years in German middle-aged populations of 0.25 kg/year. Obesity prevention needs to be targeted to specific subgroups in the population, especially to younger adults, who seem to be most vulnerable for gaining weight. Obesity intervention needs to be improved, as the majority of obese adults remained obese over time.

Association of serum vitamin D with change in weight and total body fat in a German cohort of older adults.

We examined the association of baseline serum 25-hydroxyvitamin D (25(OH)D) with change in weight and total body fat in a cohort of community-dwelling older adults from Southern Germany. A total of 735 participants of the population-based KORA-Age Study (2009-2012), aged 65-90 years, were followed for 2.9±0.1 years. Body fat was assessed with bioelectrical impedance analysis. Linear and multinomial logistic models, adjusted for baseline covariables, were used to examine the association of 25(OH)D with percentage weight and body fat change during follow-up. 25(OH)D levels were not associated with overall weight change or body fat loss. Higher 25(OH)D levels were associated with a lower likelihood of having gained >3% of body fat in women but not in men. As we cannot exclude residual confounding by outdoor physical activity and diet, our results are not sufficient to support a causal role of 25(OH)D in the etiology of obesity in Caucasian older adults.

Low serum omentin levels in the elderly population with Type 2 diabetes and polyneuropathy.

AIMS: To investigate the hypothesis that high serum levels of omentin, an adipokine with anti-inflammatory, insulin-sensitizing and cardioprotective properties, may be related to a lower risk of diabetic sensorimotor polyneuropathy. METHODS: The association between serum omentin level and polyneuropathy was estimated in people aged 61-82 years with Type 2 diabetes (47 with and 168 without polyneuropathy) from the population-based KORA F4 study. The presence of clinical diabetic sensorimotor polyneuropathy was defined as bilateral impairment of foot vibration perception and/or foot pressure sensation. Omentin levels were determined by enzyme-linked immunosorbent assay. RESULTS: Serum omentin level was inversely associated with polyneuropathy after adjustment for age, sex, height, waist circumference, hypertension, total cholesterol, smoking, alcohol intake and physical activity [odds ratio 0.45 (95% CI 0.21-0.98); P = 0.043]. Although omentin was positively correlated with adiponectin (r = 0.55, P < 0.0001) and inversely with tumour necrosis factor-α (r = -0.30, P = 0.019), additional adjustment for adiponectin and tumour necrosis factor-α had little impact on the association. CONCLUSIONS: Serum levels of omentin are reduced in people with Type 2 diabetes and diabetic sensorimotor polyneuropathy, independently of established risk factors of polyneuropathy. This association is only partially explained by biomarkers of subclinical inflammation.

Association between muscular strength and inflammatory markers among elderly persons with cardiac disease: results from the KORA-Age study.

Little is known about the association between muscle strength and inflammation in diseased individuals and particularly in cardiac patients. Thus, our purpose was to examine the association of muscular strength with the inflammatory status in older adults with and without cardiac disease. The cross-sectional analysis was based on 1079 adults aged 65-94 years, who participated in the KORA-Age study. Participants underwent an interview and extensive physical examinations including anthropometric measurements, registration of diseases and drug intake, determination of health-related behaviors, collection of blood samples for measurements of interleukin-6 and hs-CRP and muscle strength measurement using hand-grip dynamometry. Cardiac patients (n = 323) had higher levels of IL-6 and poorer muscle strength compared with older adults without cardiac disease. Among persons with cardiac diseases, muscle strength in the lower tertile compared to the upper tertile was significantly associated with increased odds of having elevated IL-6 levels (OR 3.53, 95 % CI 1.18-10.50, p = 0.024) after controlling for age, gender, body fat, alcohol intake, smoking status, diseases, medications and physical activity, whereas the association between muscle strength and hs-CRP remained borderline significant (OR 2.80, 95 % CI 0.85-9.24, p = 0.092). The same trends, with slightly lower odds ratios, were also observed in older adults without cardiac disease. Lower levels of muscular strength are associated with higher concentrations of IL-6 and hs-CRP in elderly individuals with and without cardiac disease suggesting a significant contribution of the muscular system in reducing low-grade inflammation that accompanies cardiac disease and aging.

Association of low 25-hydroxyvitamin D levels with the frailty syndrome in an aged population: results from the KORA-age Augsburg study.

OBJECTIVES: Older adults often suffer from vitamin D deficiency and from the frailty syndrome charac-terized by different physical limitations, complicating independent everyday life. Previous studies have suggested a relationship between vitamin D status and the frailty syndrome, but results have been partly inconsistent, particularly regarding the shape of the association. Therefore, our aim was to further assess the association of 25-hydroxyvitamin D (25(OH)D) serum levels and frailty in older participants. DESIGN: Cross-sectional population-based study. PARTICIPANTS: The study population included 478 men and 462 women of the KORA (COoperative health research in the Region of Augsburg)-Age study born before 1944 examined in 2009. MEASUREMENTS: Classification of participants into different frailty states was performed according to the following criteria: weight loss, exhaustion, physical inactivity, slowness, and weakness. PARTICIPANTS who met 1-2 or ≥ 3 of the 5 criteria were classified as prefrail or frail, respectively. Total 25(OH)D was measured in non-fasting serum samples with an enhanced chemiluminescence immunoassay. Sequential logistic regression models adjusted for age, sex, season, lifestyle factors, diseases and biomarkers including parathyroid hormone (PTH) were calculated. RESULTS: High levels of 25(OH)D were inversely associated with being prefrail (N=351) or frail (N=38) in the model adjusted for age, sex, season and lifestyle factors. Compared to levels <15 ng/ml, odds ratios (ORs) (95% confidence intervals (CIs) were 0.52 (0.34-0.78) for levels of 15-<20 ng/ml, 0.55 (0.37-0.81) for levels of 20-<30 ng/ml and 0.32 (0.21-0.51) for levels ≥ 30 ng/ml. Additional adjustment for potential mediators including PTH only slightly attenuated these associations. For single frailty-components, significantly decreased ORs were found for exhaustion, physical inactivity and slowness comparing 25(OH)D levels ≥ 30 ng/ml with levels <15 ng/ml. CONCLUSION: Subjects with 25(OH)D serum levels ≥ 15 ng/ml were less frequently prefrail or frail.

The use of dietary supplements among older persons in southern Germany - results from the KORA-age study.

OBJECTIVES: Current population-based surveys in Europe on the prevalence of dietary supplement (DS) use in older individuals are scarce. The aim of the present study was to investigate patterns, prevalence and determinants of non-herbal DS use in aged subjects. Furthermore, the intake amounts of vitamins and minerals from supplements were assessed. DESIGN: Cross-sectional. SETTING: Data on supplement use were available from an age- and sex-stratified random sample of the German population-based KORA (Cooperative Health Research in the Region of Augsburg)-Age study. PARTICIPANTS: 1,079 persons who were born in or before the year 1943. MEASUREMENTS: Use of dietary supplements and medications during the last seven days was recorded in a face-to-face interview in 2009. Participants were asked to bring all packages of ingested preparations to the study center. Not only vitamin/mineral supplements, but also non-vitamin non-mineral non-herbal supplements and drugs containing vitamins and minerals were coded as DS. RESULTS: The age-standardized prevalence of DS intake was 54.3% in women and 33.8% in men, respectively. The most commonly supplemented mineral and vitamin, respectively, was magnesium (31.9%) and vitamin D (21.5%) in women and magnesium (18.0%) and vitamin E (12.0%) in men. The highest intakes, compared to the German Dietary Reference Intakes, were reported for biotin, vitamin B6 and B1. Excessive intakes (equal or above the European Tolerable Upper Intake Levels (UL)) were observed especially for magnesium and vitamin E. 20.2% of the women and 32.5% of the men who took magnesium supplements regularly exceeded the UL for magnesium. In case of vitamin E this was true for 8.0% of the women and 13.6% of the men. Determinants of DS use were sex, education, smoking, physical activity, neurological diseases, and stroke. CONCLUSION: A high proportion of the general population aged 65 years and older in Southern Germany uses DS, especially supplements containing vitamins/minerals. The supplementation of vitamin D can be regarded as favorable in this age group, whereas the excessive intakes of vitamin E might be a cause of concern.

Medication costs by glucose tolerance stage in younger and older women and men: results from the population-based KORA survey in Germany.

To estimate medication costs in individuals with diagnosed diabetes, undetected diabetes, impaired glucose regulation and normal blood glucose values in a population-based sample by age and sex.Using the KORA F4 follow-up survey, conducted in 2006-2008 (n=2611, age 40-82 years), we identified individuals' glucose tolerance status by means of an oral glucose tolerance test. We assessed all medications taken regularly, calculated age-sex specific medication costs and estimated cost ratios for total, total without antihyperglycemic drugs, and cardiovascular medication, using multiple 2-part regression models.Compared to individuals with normal glucose values, costs were increased in known diabetes, undetected diabetes and impaired glucose regulation, which was more pronounced in participants aged 40-59 years than in those aged 60-82 years (cost ratios for all medications: 40-59 years: 2.85; 95%-confidence interval: 1.78-4.54, 2.00; 1.22-3.29 and 1.53; 1.12-2.09; 60-82 years: 2.04; 1.71-2.43, 1.17; 0.90-1.51 and 1.09; 0.94-1.28). Compared to individuals with diagnosed diabetes, costs were significantly lower among individuals with impaired glucose regulation across all age and sex strata, also when antihyperglycemic medication was excluded (40-59 years: 0.60; 0.36-0.98, 60-82 years: 0.74; 0.60-0.90; men: 0.72; 0.56-0.93; women: 0.72; 0.54-0.96).We could quantify age- and sex-specific medication costs and cost ratios in individuals with diagnosed diabetes, undetected diabetes and impaired glucose regulation compared to those with normal glucose values, using data of a population-based sample, with oral glucose tolerance test-based identification of diabetes states. These results may help to validly estimate cost-effectiveness of screening and early treatment or prevention of diabetes.

Patient time costs attributable to healthcare use in diabetes: results from the population-based KORA survey in Germany.

AIMS: Patient time costs have been described to be substantial; however, data are highly limited. We estimated patient time costs attributable to outpatient and inpatient care in study participants with diagnosed diabetes, previously undetected diabetes, impaired glucose regulation and normal glucose tolerance. METHODS: Using data of the population-based KORA S4 study (55-74 years, random sample of n = 350), we identified participants' stage of glucose tolerance by oral glucose tolerance test. To estimate mean patient time costs per year (crude and standardized with respect to age and sex), we used data regarding time spent with ambulatory visits including travel and waiting time and with hospital stays (time valued at a 2011 net wage rate of €20.63/h). The observation period was 24 weeks and data were extrapolated to 1 year. RESULTS: Eighty-nine to 97% of participants in the four groups (diagnosed diabetes, undetected diabetes, impaired glucose regulation and normal glucose tolerance.) had at least one physician contact and 4-14% at least one hospital admission during the observation period. Patient time [h/year (95% CI)] was 102.0 (33.7-254.8), 53.8 (15.0-236.7), 59.3 (25.1-146.8) and 28.6 (21.1-43.7), respectively. Age-sex standardized patient time costs per year (95% CI) were €2447.1 (804.5-6143.6), €880.4 (259.1-3606.7), €1151.6 (454.6-2957.6) and €589.2 (435.8-904.8). CONCLUSIONS: Patient time costs were substantial--even higher than medication costs in the same study population. They are higher in participants with diagnosed diabetes, but also in those with undetected diabetes and impaired glucose regulation compared with those with normal glucose tolerance. Research is needed in larger populations to receive more precise and certain estimates that can be used in health economic evaluation.

Serum potassium is associated with prediabetes and newly diagnosed diabetes in hypertensive adults from the general population: the KORA F4-study.

AIMS/HYPOTHESIS: Evidence suggests that low serum potassium concentrations or hypokalaemia induced by the intake of diuretics are associated with incident diabetes and increased risk for diabetes in persons with hypertension. We examined a possible association between serum potassium and prediabetes (defined as isolated impaired fasting glucose [i-IFG], isolated impaired glucose tolerance [i-IGT] or combined IFG/IGT), as well as known and newly diagnosed diabetes (NDD), in 32- to 81-year-old men and women with and without hypertension. METHODS: This cross-sectional analysis was based on 2,948 participants in the Cooperative Health Research in the Region of Augsburg (KORA) F4 study conducted in 2006-2008 in southern Germany. Serum concentrations of potassium were measured by indirect potentiometry. RESULTS: In the total sample there was no association between serum potassium concentrations and prediabetes. In hypertensive persons however serum potassium levels in the first and second quartile compared with the highest quartile were independently significantly associated with prediabetes after multivariable adjustment (OR for prediabetes, 2.02 [95% CI 1.27, 3.21] for quartile 2 and 2.00 [95% CI 1.27, 3.15] for quartile 1), while in persons without hypertension no association was found. In multinomial logistic regression analysis these findings could be confirmed. In hypertensive participants after multivariable adjustment the associations were statistically significant for i-IGT and NDD (i-IGT OR 1.23; NDD OR 1.41). However, in non-hypertensive persons, all associations between serum potassium levels and each of the categories of impaired glucose regulation were non-significant. CONCLUSIONS/INTERPRETATION: Serum potassium levels were independently associated with prediabetes and NDD in hypertensive adults from the general population.

Associations between longevity of parents and glucose regulation in their offspring: the KORA S4/F4 Study.

AIMS: Type 2 diabetes was less prevalent in studies of the offspring of centenarians and a separate study of nonagenarian siblings. We examined whether this reduction would also be found when less extreme criteria of parental longevity (a lifespan of at least 80 years) were applied. Moreover, we looked for an association between parental longevity and incidence of dysglycaemia, which has not yet been reported for a population-based study group. METHODS: Baseline and 7-year follow-up data on 55-74-year-old participants in the population-based German Cooperative Health Research in the Region of Augsburg (KORA) S4/F4 cohort study were used for the analyses. Participants whose parents had died from traumatic causes were excluded. Diabetes was assessed by validated physician diagnosis or OGTTs. Using logistic regression models, adjusted OR and 95% CIs were calculated for the associations between parental longevity and the prevalence or incidence of dysglycaemia, which was defined as including either type 2 diabetes or prediabetes (defined in this study as comprising impaired glucose tolerance [IGT] and impaired fasting glucose [IFG]). RESULTS: In age- and sex-adjusted models, the prevalence of type 2 diabetes was lower in individuals with one (OR 0.63, 95% CI 0.43, 0.93) or two (OR 0.46, 95% CI 0.25, 0.85) long-lived parents. Among participants with normal glucose tolerance at baseline, the odds of incident dysglycaemia were lower in those with one (OR 0.65, 95% CI 0.40, 1.03) or two long-lived parents (OR 0.46, 95% CI 0.22, 0.96) after adjustment for age and sex. CONCLUSIONS/INTERPRETATION: This study showed that longevity of the parents, defined by a lifespan of at least 80 years, was associated with a lower prevalence and incidence of dysglycaemia in their offspring in an older German population.

Body adiposity index, body fat content and incidence of type 2 diabetes.

AIMS/HYPOTHESIS: The aim of this study was to compare estimates of body fat content, i.e. body adiposity index (BAI), BMI and waist and hip circumferences, with respect to their ability to predict the percentage of body fat (PBF; confirmed by magnetic resonance tomography) and incident type 2 diabetes. METHODS: Associations between anthropometric measurements and PBF were evaluated in the Tübingen Lifestyle Intervention Program (TULIP; 138 men, 222 women), and between these measurements and incident type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study (9,729 men, 15,438 women) and the Cooperative Health Research in the Region of Augsburg (KORA) study (5,573 men, 5,628 women), using correlation and multivariate Cox regression analyses. RESULTS: BMI more strongly correlated with PBF (men: r = 0.81, women: r = 0.84) than BAI (r = 0.68 and 0.81, respectively), while waist circumference among men (r = 0.84) and hip circumference among women (r = 0.88) showed the strongest correlations. BAI overestimated PBF among men (mean difference -3.0%), and this error was dependent on the value of PBF. BAI was more weakly associated with diabetes risk (RRs for 1 SD, EPIC-Potsdam men: 1.62 [95% CI 1.52, 1.72], women: 1.67 [95% CI 1.55, 1.80]; KORA men: 1.62 [95% CI 1.48, 1.78], women: 1.82 [95% CI 1.65, 2.02]) compared with BMI (RRs, EPIC-Potsdam men: 1.95 [95% CI 1.83, 2.09], women 1.88 [95% CI 1.76, 2.02], KORA men 1.75 [95% CI 1.62, 1.89], women 2.00 [95% CI 1.81, 2.22]), while waist circumference showed the strongest associations (RRs: 2.17 [95% CI 2.01, 2.35], 2.33 [95% CI 2.15, 2.53], 1.81 [95% CI 1.66, 1.96] and 2.29 [95% CI 2.05, 2.57] for EPIC-Potsdam men and women and KORA men and women, respectively). CONCLUSIONS/INTERPRETATION: Waist circumference in men and hip circumference in women are better predictors of PBF than BAI and BMI. BAI was not as strong a predictor of diabetes as BMI, while waist circumference was the strongest predictor.