Dyadic Loneliness and Changes to HbA1c Among Older US Couples: The Role of Marital Support as Stress Buffer.

Objectives: Both experiencing loneliness and having a lonely partner can be psychosocial stressors, with implications for health. Yet, marital support may buffer against the cardiometabolic effects of loneliness. This study examines (1) whether own and/or partner's loneliness predict changes in HbA1c over 4 years and (2) whether marital support moderates these effects. Methods: Actor-partner interdependence models analyzed data from 1,854 older couples who provided psychosocial and biomarker data at two timepoints (2008/2012 or 2010/2014) of the Health and Retirement Study. Results: Neither partner's loneliness predicted changes in HbA1c overall. However, significant interactions indicated that both own baseline loneliness and partner's baseline loneliness predicted significant increases to HbA1c over 4 years among those who reported below-average marital support. Discussion: Both the experience of loneliness and loneliness of a dyadic partner may have longitudinal consequences for cardiometabolic health. However, these effects are contingent upon perceived quality of the marriage, specifically marital support.