The CARLA study (Cardiovascular Disease, Living and Ageing in Halle) is a population-based cohort study of the elderly general population of the city of Halle (Saale) aged 45-83 years. The aim is to investigate established cardiovascular risk factors and a reduced heart rate variability (HRV) as indicator of autonomous dysfunction. In total, 1779 probands (812 women and 967 men) were investigated at baseline. Of those, 1436 participants were re-examined at a 4-years follow-up. The corresponding response rates were 64.1% in the baseline and 92% in the follow-up investigation. In the cross-sectional analysis a clear decrease was found in all parameters of HRV with increasing age, but no consistent associations to cardiovascular classical risk factors and diseases could be shown. Compared to other German cohorts a striking risk constellation was found consisting of high prevalence of hypertension, frequent occurrence of central overweight (measured by waist-hip ratio) and high prevalence of diabetes mellitus. These findings will be further scrutinized in the ongoing analyses of the 4-year follow-up and the 10-years follow-up which will start in 2012.