Cognitive Functioning is Related to Physical Functioning in a Longitudinal Study of Women at Mid-Life

Background. Studies have reported declines with age in cognitive or physical functioning, but rarely identify whether these are parallel or linked events in the same study.

Objective. The objective of the study was to determine: 1) if cognitive functioning was related to physical functioning and whether this relationship persisted after adjustment for age, menopause status, metabolic status, depression and socioeconomic resources; and, 2) if changes in physical functioning were associated with changes in cognitive functioning over a four-year follow-up period.

Methods. Data were from the Study of Women’s Health Across the Nation (SWAN), a multi-site, longitudinal study of women age 46-56 years at Follow-up 4. Three data waves (Follow-up 4, 6 and 8) included measures of physical functioning perception [MOS-SF36] and cognitive functioning [Symbol Digit Modality Test (SDMT), Digit Span Backward Test (DSBT), and East Boston Memory Test (EBMT)] (N=2,405).

Results. Women with lower cognitive functioning scores also had lower perceived physical functioning scores. Although adjustment for age, race, study site, metabolic syndrome status, menopause status, depression and socioeconomic resources attenuated the association between perceived physical functioning and both SDMT and EBMT, these associations remained statistically significant. Additionally, the four-year change in perceived physical functioning was significantly associated with the four-year change in the EBMT.

Conclusions. At midlife, there were associated declines in cognitive and perceived physical functioning scores, commencing at the mid-life in women.