Dehydroepiandrosterone and cognitive impairment and impact in cardiovascular mortality among men and women 55 years and older

Aim. To evaluate possible associations between low dehydroepiandrosterone sulfate (DHEAS) levels and cognitive impairment and their impact in cardiovascular mortality among the population 55 years and older. Material and methods. The present study was carried out as part of the prospective cohort survey "Stress, aging and health" in Russia. 1876 men and women aged 55 years and older were examined. Cognitive function was assessed at baseline and after 3 years using the Mini- Mental State Examination scale; a decrease in cognitive function corresponded to a sum of scores less than 24 out of 30 points. DHEAS levels were assessed in serum samples. All participants were ranked according to quintiles of DHEAS levels (>2.61 μmol, 2.34-2.61 μmol/L, 1.60-2.33 μmol/L, 1.05-1.59 μmol/L, <1.05 μmol/L). Mortality was estimated from the permanent death registry using standard methods. During the follow-up period (median 12 years), 315 deaths from CVD were registered. Results. A total of 1876 participants aged 55 years and older (48% men and 52% women) were included in the study. The frequency of cognitive function, both baseline and after three years in men was almost independent of the DHEAS level, while in women, low levels of cognitive function were predominant in the first quintile of DHEAS. With decreasing DHEAS levels, cognitive function decreased significantly in women (1 quintile vs. 5 quintiles of DHEAS), but no such associations were found in men. In a population of men 55 years and older, both cognitive impairment (OR: 2.08; 95% CI 1.49 to 2.92) and low DHEAS levels (OR: 1.60; 95% CI 1.05 to 2.44) were significantly associated with cardiovascular mortality. Similar results were obtained in the cohort of women — the risk of cardiovascular mortality was increased in the presence of cognitive impairment by 2.3-fold (p<0.05), low DHEAS by 1.6-fold (p<0.05), respectively. The simultaneous presence of these disorders was significantly associated with CVD mortality, but only in women. Conclusion. Based on the results of the present study, an association between baseline DHEAS levels and baseline cognitive impairment was found, but only in a female population. A prospective follow-up assessment of cognitive function failed to support the hypothesis that low DHEAS levels may predict greater decline in cognitive function. However, a significant cumulative contribution of cognitive impairment combined with low DHEAS concentration to cardiovascular mortality was observed at 12-year follow-up, but only in women.