Objective: The death or illness of a spouse negatively affects a partner’s health, but little is known about the effect on blood glucose (glycemic) levels. This study investigates the extent to which a spouse’s declining health or death is associated with changes in the glycemic levels of older adults. Method: Data come from a nationally representative longitudinal sample of 597 Taiwanese (aged 54 to 90). We use changes in spousal health and death of a spouse to predict changes in glycosylated hemoglobin (HbA_1c) levels over a 6-year period. Results: A decline in spousal health is associated with increased HbA_1c levels for women, but not for men. The death of a healthy spouse is associated with increased HbA_1c levels for both genders. Discussion: Stressful life transitions may compromise the glycemic levels of older adults. Taking on a caregiving role may erode some of the benefits of marriage and interfere with women’s maintenance of their own health.