Multimorbidity and Functional Disability among Older Adults: The Role of Inflammation and Glycemic Status - An Observational Longitudinal Study.

INTRODUCTION

Specific multimorbidity combinations, in particular those including arthritis, stroke, and cognitive impairment, have been associated with high burden of activities of daily living (ADL)-instrumental activities of daily living (IADL) disability in older adults. The biologic underpinnings of these associations are still unclear.

METHODS

Observational longitudinal study using data from the Health and Retirement Study (N = 8,618, mean age = 74 years, 58% female, 25% non-white) and negative binomial regression models stratified by sex to evaluate the role of inflammatory and glycemic biomarkers (high-sensitivity C-reactive protein (hs-CRP) and HbA1c) in the association between specific multimorbidity combinations (grouped around one of eight index diseases: arthritis, cancer, cognitive impairment, diabetes, heart disease, hypertension, lung disease, and stroke; assessed between 2006 and 2014) and prospective ADL-IADL disability (2 years later, 2008-2016). Results were adjusted for sociodemographic characteristics, body mass index, number of coexisting diseases, and baseline ADL-IADL score.

RESULTS

Multimorbidity combinations indexed by arthritis (IRR = 1.1, 95% CI = 1.01-1.20), diabetes (IRR = 1.19, 95% CI = 1.09-1.30), and cognitive impairment (IRR = 1.11, 95% CI = 1.01-1.23) among men and diabetes-indexed multimorbidity combinations (IRR = 1.07, 95% CI = 1.01-1.14) among women were associated with higher ADL-IADL scores at increasing levels of HbA1c. Across higher levels of hs-CRP, multimorbidity combinations indexed by arthritis (IRR = 1.06, 95% CI = 1.02-1.11), hypertension (IRR = 1.06, 95% CI = 1.02-1.11), heart disease (IRR = 1.06, 95% CI = 1.01-1.12), and lung disease (IRR = 1.14, 95% CI = 1.07-1.23) were associated with higher ADL-IADL scores among women, while there were no significant associations among men.

CONCLUSION

The findings suggest potential for anti-inflammatory management among older women and optimal glycemic control among older men with these particular multimorbidity combinations as focus for therapeutic/preventive options for maintaining functional health.