Bernd Kowall

Mobile phone base stations and adverse health effects: phase 1 of a population-based, cross-sectional study in Germany

Objective: The aim of this first phase of a cross-sectional study from Germany was to investigate whether proximity of residence to mobile phone base stations as well as risk perception is associated with health complaints. Methods: The researchers conducted a population-based, multi-phase, cross-sectional study within the context of a large panel survey regularly carried out by a private research institute in Germany. In the initial phase, reported on in this paper, 30 047 persons from a total of 51 444 who took part in the nationwide survey also answered questions on how mobile phone base stations affected their health. A list of 38 health complaints was used. A multiple linear regression model was used to identify predictors of health complaints including proximity of residence to mobile phone base stations and risk perception. Results: Of the 30 047 participants (response rate 58.6%), 18.7% of participants were concerned about adverse health effects of mobile phone base stations, while an additional 10.3% attributed their personal adverse health effects to the exposure from them. Participants who were concerned about or attributed adverse health effects to mobile phone base stations and those living in the vicinity of a mobile phone base station (500 m) reported slightly more health complaints than others. Conclusions: A substantial proportion of the German population is concerned about adverse health effects caused by exposure from mobile phone base stations. The observed slightly higher prevalence of health complaints near base stations can not however be fully explained by attributions or concerns.

Mobile phone base stations and adverse health effects: phase 2 of a cross-sectional study with measured radio frequency electromagnetic fields

Objective: The aim of the cross-sectional study was to test the hypothesis that exposure to continuous low-level radio frequency electromagnetic fields (RF-EMFs) emitted from mobile phone base stations was related to various health disturbances. Methods: For the investigation people living mainly in urban regions were selected from a nationwide study in 2006. In total, 3526 persons responded to a questionnaire (response rate 85%). For the exposure assessment a dosimeter measuring different RF-EMF frequencies was used. Participants answered a postal questionnaire on how mobile phone base stations affected their health and they gave information on sleep disturbances, headaches, health complaints and mental and physical health using standardised health questionnaires. Information on stress was also collected. Multiple linear regression models were used with health outcomes as dependent variables (n = 1326). Results: For the five health scores used, no differences in their medians were observed for exposed versus non-exposed participants. People who attributed adverse health effects to mobile phone base stations reported significantly more sleep disturbances and health complaints, but they did not report more headaches or less mental and physical health. Individuals concerned about mobile phone base stations did not have different well-being scores compared with those who were not concerned. Conclusions: In this large population-based study, measured RF-EMFs emitted from mobile phone base stations were not associated with adverse health effects.

Age at menarche and its association with the metabolic syndrome and its components: results from the KORA F4 study.

Objective 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. Design 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. Results 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). Conclusion 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.

Prediction models for incident type 2 diabetes mellitus in the older population: KORA S4/F4 cohort study.

Diabet. Med. 27, 1116–1123 (2010)

Hemoglobin A1c and glucose criteria identify different subjects as having type 2 diabetes in middle-aged and older populations: The KORA S4/F4 Study

Abstract Objective. The American Diabetes Association (ADA) has recently recommended HbA1c for diagnosing diabetes as an alternative to glucose-based criteria. We compared the new HbA1c-based criteria for diagnosis of diabetes and prediabetes with the glucose-based criteria. Research design and methods. In the population-based German KORA surveys (S4/F4) 1,764 non-diabetic participants aged 31–60 years and 896 participants aged 61–75 years underwent measurements of HbA1c, fasting plasma glucose (FPG), and 2-h glucose. Results. Only 20% of all subjects diagnosed with diabetes by glucose or HbA1c criteria had diabetes by both criteria; for prediabetes, the corresponding figure was 23%. Using HbA1c ≥ 6.5%, the prevalence of diabetes was strongly reduced compared to the glucose criteria (0.7% instead of 2.3% in the middle-aged, 2.9% instead of 7.9% in the older subjects). Only 32.0% (middle-aged) and 43.2% (older group) of isolated impaired glucose tolerance (i-IGT) cases were detected by the HbA1c criterion (5.7% ≤ HbA1c < 6.5%). Conclusion. By glucose and the new HbA1c diabetes criteria, different subjects are diagnosed with type 2 diabetes in middle-aged as well as older subjects. The new HbA1c criterion lacks sensitivity for impaired glucose tolerance.

Older Subjects With Diabetes and Prediabetes Are Frequently Unaware of Having Distal Sensorimotor Polyneuropathy The KORA F4 Study

OBJECTIVE Distal sensorimotor polyneuropathy (DSPN) is a severe complication of type 2 diabetes. This study aimed to assess the prevalence of unawareness of DSPN in prediabetes and diabetes in a sample of the older population of Augsburg, Germany. RESEARCH DESIGN AND METHODS Glucose tolerance status was determined in 61- to 82-year-old participants of the population-based KORA F4 Study (2006–2008) (n = 1,100). Clinical DSPN was defined as the presence of bilaterally impaired foot-vibration perception and/or bilaterally impaired foot-pressure sensation. DSPN case subjects were considered unaware of their condition when answering “no” to the question, “Has a physician ever told you that you are suffering from nerve damage, neuropathy, polyneuropathy, or diabetic foot?” RESULTS Clinical DSPN was prevalent in 154 (14%) participants, 140 of whom were unaware of their disorder. At a prevalence of 23.9% (95% CI 12.6–38.8), participants with combined impaired fasting glucose and impaired glucose tolerance had the highest prevalence of DSPN. Of these, 10 of 11 (91%) were unaware of having clinical DSPN. Participants with known diabetes had an equally high prevalence of DSPN [22.0% (16.2–28.9)], with 30 of the 39 (77%) DSPN case subjects unaware of having the disorder. Among subjects with known diabetes who reported to have had their feet examined by a physician, 18 of 25 (72%) clinical DSPN case subjects emerged unaware of having DSPN. CONCLUSIONS Our findings showed a high prevalence of unawareness of having clinical DSPN among the prediabetic and diabetic groups and an insufficient frequency of professional foot examinations, suggesting inadequate attention to diabetic foot prevention practice.

The potential of novel biomarkers to improve risk prediction of type 2 diabetes

The incidence of type 2 diabetes can be reduced substantially by implementing preventive measures in high-risk individuals, but this requires prior knowledge of disease risk in the individual. Various diabetes risk models have been designed, and these have all included a similar combination of factors, such as age, sex, obesity, hypertension, lifestyle factors, family history of diabetes and metabolic traits. The accuracy of prediction models is often assessed by the area under the receiver operating characteristic curve (AROC) as a measure of discrimination, but AROCs should be complemented by measures of calibration and reclassification to estimate the incremental value of novel biomarkers. This review discusses the potential of novel biomarkers to improve model accuracy. The range of molecules that serve as potential predictors of type 2 diabetes includes genetic variants, RNA transcripts, peptides and proteins, lipids and small metabolites. Some of these biomarkers lead to a statistically significant increase of model accuracy, but their incremental value currently seems too small for routine clinical use. However, only a fraction of potentially relevant biomarkers have been assessed with regard to their predictive value. Moreover, serial measurements of biomarkers may help determine individual risk. In conclusion, current risk models provide valuable tools of risk estimation, but perform suboptimally in the prediction of individual diabetes risk. Novel biomarkers still fail to have a clinically applicable impact. However, more efficient use of biomarker data and technological advances in their measurement in clinical settings may allow the development of more accurate predictive models in the future.

Postchallenge Hyperglycemia Is Positively Associated With Diabetic Polyneuropathy The KORA F4 study

OBJECTIVE To assess the prevalence of distal sensorimotor polyneuropathy (DSPN) in an older population and to examine its relationship with prediabetes. RESEARCH DESIGN AND METHODS Glucose tolerance status was determined in 61- to 82-year-old participants (n = 1,100) of the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4 Survey (2006–2008). Clinical DSPN was defined as bilaterally impaired foot-vibration perception and/or foot-pressure sensation. RESULTS Prevalence of clinical DSPN was similar in subjects with known diabetes (22.0%) and subjects with combined impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) (23.9%). Among prediabetic subgroups, IFG-IGT, but not isolated-IFG and -IGT, was associated with a higher risk of clinical DSPN, compared with normal glucose tolerance. A J-shaped association was observed between clinical DSPN and quartiles of 2-h postchallenge glucose, but not with fasting glucose and HbA1c levels. CONCLUSIONS Subjects with IFG-IGT and known diabetes had a similar prevalence of clinical DSPN. Elevated 2-h postload glucose levels appeared important for disease risk.

Retinol-binding protein 4 is associated with prediabetes in adults from the general population: the Cooperative Health Research in the Region of Augsburg (KORA) F4 Study.

OBJECTIVE We examined the association between retinol-binding protein 4 (RBP4), a novel adipokine, and prediabetes (isolated impaired fasting glucose [i-IFG], isolated impaired glucose tolerance [i-IGT], and combined IFG and IGT) in men and women aged 32–81 years. RESEARCH DESIGN AND METHODS The analysis was based on 2,614 participants without previously diagnosed diabetes and those with newly diagnosed diabetes of the Cooperative Health Research in the Region of Augsburg (KORA) F4 Study, conducted from 2006 to 2008 in southern Germany. Plasma RBP4 was analyzed by immunonephelometry. RESULTS In logistic regression analysis, RBP4 levels in the fourth quartile versus the first quartile were significantly associated with prediabetes (i-IGT, i-IFG, and IFG/IGT; reference normal glucose tolerance) independent of known metabolic risk factors and lifestyle variables (odds ratio 1.63 [95% CI 1.17–2.27] after multivariable adjustment). Stratification by sex showed generally similar results. CONCLUSIONS RBP4 levels were associated with prediabetes in individuals from the general population. Prospective studies investigating the impact of RBP4 on the development of glucose intolerance are needed.

Association of Subclinical Inflammation With Polyneuropathy in the Older Population KORA F4 study

OBJECTIVE Inflammatory processes have been implicated in the pathogenesis of diabetic distal sensorimotor polyneuropathy (DSPN), but their possible relationship has not been assessed at the population level. RESEARCH DESIGN AND METHODS We determined serum concentrations of mediators of subclinical inflammation among 1,047 participants 61–82 years of age from the population-based Cooperative Health Research in the Region of Augsburg (KORA) F4 study (Germany). Logistic and linear regression models were fitted to assess associations between immune mediators (log-transformed) and the presence of clinical DSPN (dichotomous variable) or Michigan Neuropathy Screening Instrument (MNSI) examination score (continuous variable), respectively. RESULTS Serum concentrations of the anti-inflammatory interleukin (IL)-1 receptor antagonist (IL-1RA) were positively associated with the presence of DSPN and higher MNSI scores in age-adjusted and sex-adjusted analyses, whereas IL-6, IL-18, and soluble intercellular adhesion molecule-1 were positively associated with only MNSI scores. No associations were observed for adiponectin, C-reactive protein, or tumor necrosis factor-α. Associations for IL-1RA and IL-6 with the MNSI score remained statistically significant after additional adjustment for waist circumference, height, hypertension, cholesterol, smoking, alcohol intake, physical activity, history of myocardial infarction or stroke, presence of neurological conditions, and use of nonsteroidal anti-inflammatory drugs. CONCLUSIONS We conclude that DSPN is linked to proinflammatory and anti-inflammatory, possibly compensatory, processes in the older general population. Future studies should clarify the temporal sequence and causality of these associations.