Association of Body Fat With Health-Related Quality of Life and Depression in Nonagenarians: The Mugello Study.

OBJECTIVES: The association of body fat with health status and depression in the oldest old is still debated. The aim of this cross-sectional study is to investigate the association of body fat with health-related quality of life and depression in a sample of nonagenarians. DESIGN: Data are from the Mugello study, a community-based project conducted in Italian older adults aged 90 years. SETTING AND PARTICIPANTS: Total body fat was assessed by body impedance assessment. Participants were divided into 3 groups according to gender-specific tertiles of body fat percentage (BF%). Self-perceived mental and physical health status were assessed by the Mental Component Summary (MCS) and the Physical Component Summary (PCS) subscales derived from the 12-item Short Form Health Survey. Lower scores of MCS and PCS indicated poorer mental health and physical health status, respectively. Depressive symptoms were assessed using the 15-item Geriatric Depression Scale, and a score ≥5 was used to identify participants with depression. RESULTS: The mean age of 251 study participants was 92.5 years, and 173 (68.9%) were women. Participants were included in the low (n = 83), medium (n = 83), and high (n = 85) BF% groups. In the whole sample, mean scores at PCS progressively declined with the increasing BF% group (P = .004). This association was stronger in women, although no significant interaction was observed between the gender and BF% group (P = .63). No significant association between BF% and MCS was documented. Medium and high BF% were associated with a significantly higher probability of depression as compared with low BF% [odds ratio (OR) 2.15, 95% confidence interval (CI) 1.04-4.44, and OR 2.15, 95% CI 1.06-4.34, respectively]. This association was stronger in women, although no significant interaction was observed between gender and BF% group (P = .70). CONCLUSIONS AND IMPLICATIONS: High BF% is significantly positively associated with poor health-related quality of life and depression, underpinning the clinical relevance to test BF% in older adults. These associations appear to be stronger in women than in men, highlighting the need to investigate deep inside this gender discrepancy.