THE PAQUID SURVEY AND CORRELATES OF SUBCLINICAL HYPOTHYROIDISM IN ELDERLY COMMUNITY RESIDENTS IN THE SOUTH-WEST OF FRANCE

The aim of this study was to assess the prevalence of increased thyroi d-stimulating hormone (TSH) levels (subclinical or undiagnosed hypothy roidism) in a representative sample of a community-living elderly popu lation and to examine the relationships with cognitive functions and d epressive symptoms. An epidemiological study was made of a cohort of 2 792 subjects over 65 years of age. A blood sample was obtained from 42 5 volunteers of this cohort and assayed for TSH. Every subject partici pating in the study was interviewed and given a battery of neuropsycho logical tests by a psychologist. Three hundred and eighty-one subjects (89.7%) had normal TSH levels; 18 subjects (4.2%) had TSH lower than 0.4 mu U/ml, associated in two of them with hyperthyroxinaemia. Twenty -six subjects (6.1%) had increased TSH levels, associated in 18 of the m with a normal free thyroxine level and in eight with a low free thyr oxine level. Increased TSH levels were significantly linked with femal e sex and with the presence of symptoms of depression on the CES-D sca le but not with impairment of cognitive function.