Changes in the prevalence of the metabolic syndrome among adults in Germany – German Health Interview and Examination Surveys 1997 – 99 and 2008 – 11

Objective: To investigate changes over time in the prevalence of metabolic risk factor clustering as defined by the metabolic syndrome (MetS) among adults in Germany.

Design/Methods: We analysed data from national health interview and examination surveys 1997 – 99 and 2008 – 11 for adults in Germany 18 – 79 years of age. MetS was defined as the presence of three or more metabolic risk factors using the following factors and cut-offs: serum glucose ≥5.6 mmol/l (7.0 mmol/l for fasting less than four hours); blood pressure ≥130/85 mmHg; triglycerides ≥1.7 mmol/l (2.1 mmol/l for fasting less than four hours); high-density-lipoprotein cholesterol (HDL-C) ≤1.0/1.3 mmol/l (HDL-C; women/men); waist circumference ≥80/94 cm (WC; women/men). Drug treatment for elevated triglycerides and elevated HDL-C, antidiabetic drug treatment, and antihypertensive drug treatment among persons with a history of hypertension were further considered for defining the respective risk factors. Changes in weighted prevalence over time standardized to the population 2010 were calculated using SAS 9.4 survey procedures for complex sample designs, overall and within strata of sex, age (18 – 39, 40 – 64, 65 – 79 years) and social status (low, intermediate, high). Sensitivity analyses were conducted considering additional metabolic markers (HbA1c, hs-CRP) and a fasting period of eight hours.

Results: In both surveys, MetS prevalence was consistently and positively associated with male sex, older age, and lower social status. There was a consistent decrease in MetS prevalence across social status strata among men. Among women, a decrease over time was restricted to women with low social status. Decreases in MetS prevalence were statistically significant only among middle-aged men and women (40 – 64 years) and largely due to decreases in triglycerides. In contrast, elevated blood pressure including treated hypertension significantly increased among men and decreased among women, and elevated serum glucose including antidiabetic treatment did not change in either sex. Results persisted in sensitivity analyses.

Discussion/Public health relevance: Between the 1997 – 99 and 2008 – 11 survey periods, the overall MetS prevalence slightly decreased in both sexes. The MetS is still highly prevalent among adults 18 – 79 years in Germany indicating a high risk of cardiovascular morbidity and mortality. Observed differences across strata of age and social status deserve refined analyses and continued monitoring.