Glycemic control and disability-free survival in hypoglycemic agent-treated community-dwelling older patients with type 2 diabetes mellitus.

Aim Although lower glycated hemoglobin (HbA_1c) has been believed to be an important marker of improvement of glycemic control in order to maintain better quality of life for patients with diabetes mellitus, a too low HbA_1c might be harmful in older adults. We investigated whether this was the case with respect to risk of support/care-need certification in community-dwelling older patients with type 2 diabetes mellitus. Methods We analyzed 184 diabetes patients aged 65-94 years receiving glucose-lowering medication/insulin. The end-points were first support/care-need certification and/or death. The relationships between four classes of HbA_1c and risk of support/care-need certification and/or death were determined using the Cox proportional hazards regression model. Results During 5 years, 42 first support/care-need certifications and 13 deaths occurred. The association of HbA_1c with risk of support/care-need certification after adjustment for age, sex and confounding variables was J-shaped, with the nadir at an HbA_1c level of 6.5 to <7.0%, and with an increased risk of support/care-need certification (HR 3.45, 95% CI 1.02-11.6, P = 0.046) at an HbA_1c level of <6.0% compared with the nadir. When compared with patients with HbA_1c ≥6.0%, those with HbA_1c <6.0% showed a higher risk of support/care-need certification as a result of dementia (HR 12.5, 95% CI 3.00-52.2, P = 0.001), but not as a result of arthralgia/fracture, stroke or other disorders. Conclusions These observations show that a too low HbA_1c might be associated with a later risk of incident disability as a result of dementia in community-dwelling older diabetes patients. Geriatr Gerontol Int 2017; 17: 1858-1865. [ABSTRACT FROM AUTHOR]