Age‐Specific Associations of Household Size With Sedentary Behavior and Cardiometabolic Risk in Korean Adults
Eunsook SungBackground
Single‐person households account for approximately 35% of the Korean households. Household size (HS) may be associated with cardiometabolic health through behavioral pathways, particularly sedentary behavior (SB), but age‐specific evidence is limited.
Methods
We analyzed pooled cross‐sectional data from 34,668 adults aged ≥ 19 years in the Korea National Health and Nutrition Examination Survey (KNHANES), 2014–2023. Survey‐weighted linear regression models stratified by age (19–29, 30–44, 45–59, 60–74, and ≥ 75 years) examined HS (one‐person [HS1] to five‐or‐more‐person [HS5+]) in relation to sedentary time and cardiometabolic markers. Models adjusted for sex, smoking, alcohol use, income, and education. We applied false discovery rate correction and additionally adjusted for marital status in sensitivity analyses.
Results
Adults in HS1 had greater sedentary time at ages 19–29, 30–44, and 60–74 years. The largest difference occurred at ages 30–44 years (HS5+ vs. HS1: adjusted difference −98 min/day, 95% confidence interval [CI] −123–−72; geometric mean ratio 0.78, 95% CI 0.74–0.83; β = −0.245, q < 0.001). At ages 45–59 years, systolic blood pressure (SBP) was higher in HS1 than HS5+ (HS5+ vs. HS1: β = −3.13 mmHg, q = 0.036). At ages 30–44 years, HS4 and HS5+ had lower high‐density lipoprotein cholesterol than HS1 (HS5+: β = −3.74 mg/dL, q < 0.001). Body mass index, waist circumference, triglycerides, fasting glucose, and glycated hemoglobin were not associated with HS after correction. Core findings persisted after marital‐status adjustment.
Conclusions
Living alone was consistently associated with greater sedentary time and, in working‐age adults, with higher SBP. Adults living alone may warrant closer attention in public health surveillance and future research on SB.