Association of insulin resistance and health-related quality of life with mild cognitive impairment during aging

BACKGROUND: Previous studies have shown an association between dementia and diabetes. This study focused on examining whether insulin resistance is a risk factor for mild cognitive impairment (MCI). We also evaluated whether common cardiovascular risk factors or depressive symptoms modify the risk of MCI along with insulin resistance and compared the health-related quality of life (HRQoL) with or without MCI. METHODS: CERAD) total score at the follow-up. The changes in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and fasting insulin level during the follow-up were determined. Smoking, alcohol consumption, physical activity, depressive symptoms, and HRQoL were obtained by questionnaire. Body weight, height, blood pressure, and low-density lipoprotein (LDL) cholesterol were measured at baseline and follow-up. Adjustments were made for baseline cognitive performance, professional education and physical activity. RESULTS: Greater increases in HOMA-IR (OR 2.20, 95% CI 1.05-4.62) and fasting insulin (OR 3.49, 95% CI 1.48-8.23) increased the risk of MCI. Lower cognitive performance at baseline (OR 6.33; 95% CI 3.27-12.29), lower level of education (OR 3.94, 95% CI 1.76-8.81) and lower level of physical activity (OR 2.44, 95% CI 1.06-5.65) also increased the risk of MCI at follow-up. There was a greater decline in health-related quality of life among the MCI group. CONCLUSION: Insulin resistance is a risk factor for MCI and MCI causes worsening of HRQoL during aging.