Impact of long-hours family caregiving on non-fatal coronary heart disease risk in middle-aged people: Results from a longitudinal nationwide survey in Japan

Aim: The effects of family caregiving, especially long-hours caregiving, on coronary heart disease (CHD) are debatable. We examined the impact of family caregiving on incident non-fatal CHD. Methods: We used data from the Longitudinal Survey of Middle-Aged and Elderly Persons from 2005 to 2010, a nationwide panel survey for Japanese people aged 50–59 years in 2005 (baseline). After we excluded non-respondents and people with missing key variables at baseline, 25 121 individuals without CHD, stroke or cancer were followed up for a mean of 4.6 years. The exposure was assessed at baseline by three indicators: (i) family caregiving; (ii) hours spent caregiving; and (iii) kinship type of care recipient. The non-fatal CHD incidence was identified according to questionnaire responses from 2006 to 2010. Results: Cox's proportional hazards analysis did not show a statistically significant association between family caregiving and incident non-fatal CHD (hazard ratio [HR] 1.13, 95% confidence interval [CI] 0.92–1.40). Caregivers who spent 20–69 h per week on care showed a statistically significant increased risk for non-fatal CHD (HR 1.78, 95% CI 1.23–2.58) compared with non-caregivers; whereas this increased risk was statistically significant only among women (HR 1.98, 95% CI 1.27–3.08), but not among men (HR 1.35, 95% CI 0.67–2.71). Kinship type of care recipient did not make a significant difference to the effects of family caregiving on incident non-fatal CHD. Conclusions: Long-hours family caregiving could be an independent risk factor for incident non-fatal CHD among middle-aged women in Japan. Geriatr Gerontol Int 2017; 17: 2109–2115.