Sex-Specific Risk Factors for Dynapenia in Korean Middle-Aged and Older Adults: A Cross-Sectional Study Based on the Korea National Health and Nutrition Examination Survey 2014–2019

<b>Background/Objectives</b>: Dynapenia, characterized by an age-related decline in muscle strength, has recently gained attention as a major public health concern. While prior studies identified individual risk factors, little is known about how these factors cluster differently by sex. This study investigated sex-specific risk factors and their combinations associated with dynapenia among Korean middle-aged and older adults. <b>Methods</b>: We analyzed 22,850 participants aged ≥ 40 years from the 2014-2019 Korea National Health and Nutrition Examination Survey. Dynapenia was defined as handgrip strength < 28 kg in men and <18 kg in women. Sex-stratified multivariable logistic regression identified independent predictors, and association rule mining (ARM) detected synergistic risk factor combinations. <b>Results</b>: Dynapenia was more prevalent in women (13.9%) than in men (8.5%). Advancing age, physical inactivity, lack of resistance exercise, and a high incidence of diabetes and stroke were consistent risk factors in both sexes. However, ARM revealed distinct clustering patterns: behavioral factors predominated in men, whereas socioeconomic disadvantage and metabolic comorbidities were more relevant in women with dynapenia. <b>Conclusions</b>: These findings emphasize the need for sex-specific prevention strategies for dynapenia, promoting resistance exercise among men and addressing both inactivity and socioeconomic barriers in women.