Coping and positive affect predict longitudinal change in glycosylated hemoglobin.

OBJECTIVE This study investigated whether different psychosocial factors predicted levels of glycosylated hemoglobin (HbA1c) over time, after adjusting for covariates and baseline level of HbA1c. DESIGN These questions were investigated with a longitudinal sample (N = 97, age = 61-91) of older women without diabetes. HbA1c levels and psychosocial measures were obtained at baseline and 2-year follow-up. MAIN OUTCOME MEASURES Coping strategies, positive affect, medical history, and health behaviors were assessed using self-administered questionnaires. HbA1c were obtained during the respondents' overnight stay at the General Clinical Research Center (GCRC) at the University of Wisconsin-Madison. RESULTS AND CONCLUSION Regression analyses showed that higher levels of problem-focused coping, venting, and positive affect predicted lower levels of HbA1c, after controlling for baseline HbA1c and sociodemographic and health factors. Furthermore, positive affect was found to moderate the effects of problemfocused coping (active, instrumental social support, suppressing competing activities). The pattern of interaction showed that the adverse effects of low problem-focused coping on cross-time changes in HbA1c were amplified among those who also had low levels of positive affect.