Background: We investigated the environmental and genetic sources of interindividual variability in serum aldosterone level in a large, community-based sample.
Methods: We examined the relation of serum aldosterone to vascular risk factors, urine sodium, and candidate single nucleotide polymorphisms in 2891 Framingham Offspring Study participants (53.2% women, mean age 59 years) using multivariable linear regression. Multivariable logistic regression was used to identify predictors of high (top quartile) and low (lowest quartile) serum aldosterone values. We estimated heritability of serum aldosterone via variance-component methods and evaluated linkage via a 10-cM-density genome scan.
Results: Clinical variables related to higher serum aldosterone level included female sex, diuretic treatment, and a higher total/high density lipoprotein cholesterol ratio. A high urinary sodium excretion, postmenopausal status (without hormone replacement therapy), increased pulse pressure, and prevalent cardiovascular disease were related to lower serum aldosterone values. Urinary sodium was the strongest correlate of serum aldosterone (R2= 10%). Serum aldosterone levels did not differ by genotype in the aldosterone synthase (CYP11B2c.1-344C>T) and the mineralocorticoid receptor (NR3C2c.754A>G) genes. The estimated heritability of serum aldosterone was 0.10. No chromosomal region attained a log-of-the-odds score >1 in multipoint linkage analysis.
Conclusions: We observed a complex relation between serum aldosterone and vascular risk factors. The genetic contribution to serum aldosterone level was modest.