Lead concentrations in elderly urban people related to blood pressure and mental performance: results from a population-based study.
BACKGROUND: The Kungsholmen project is a longitudinal study of ageing and dementia conducted in Stockholm in 1987. In a 1994-96 follow-up, 804 subjects had their blood samples analyzed for lead. METHODS: Lead concentration in blood in an elderly population aged 75+ (mean age of 88.4 years) was studied in relation to age, blood pressure (BP), body mass index (BMI), cognitive function measured with Mini-Mental State Examination (MMSE), gender, and smoking. RESULTS: The mean blood lead level (n = 762) was 3.7 microg/dL (0.18 micromol/L) whole blood with a standard deviation of 2.3, (0.11). There was a contribution of gender with men having higher blood lead levels than women (beta = -0.20; P = 0.000001) but not of smoking habits (beta = 0.07; P = 0.08) when these variables were entered into a multiple regression model with lead as the dependent variable (R = 0.22; P < 0.000001). Different multiple regression models were tested with lead as the dependent variable. No relation was found between lead concentrations and age, BMI, systolic BP, diastolic BP, or MMSE. Systolic and diastolic BP were correlated to BMI (R = 0.10; P = 0.01 and R = 0.22; P = 0.000 001, respectively). CONCLUSIONS: In this elderly population from a specified area of Stockholm it is unlikely that lead exposure affects BP or cognition. However, high lead levels in blood may reflect earlier occupational exposure or life style factors.