Natural history of prediabetes in older adults from a population-based longitudinal study.

BACKGROUND: The natural history of prediabetes in older adults remains unknown.

OBJECTIVES: To assess the rate at which prediabetes progresses to diabetes, leads to death or reverts to normoglycaemia in older adults and to identify prognostic factors related to different outcomes of prediabetes.

METHODS: In the Swedish National Study on Aging and Care-Kungsholmen, 2575 diabetes-free participants aged ≥60 years were examined at baseline and followed for up to 12 years. At each wave, diabetes was diagnosed via medical examination, antidiabetic drug use, medical records or glycated haemoglobin (HbA1c) ≥6.5%. Prediabetes was defined as HbA1c ≥5.7% and normoglycaemia as HbA1c <5.7% in diabetes-free participants. Data were analysed with multinomial logistic regression.

RESULTS: At baseline, 918 (36%) individuals had prediabetes. Of them, 204 (22%) reverted to normoglycaemia (3.4/100 person-years, 95% CI 5.6-12.3), 119 (13%) developed diabetes (2.0/100 person-years, 95% CI 1.7-2.4) and 215 (23%) died (13.0/100 person-years, 95% CI 11.4-14.9) during the 12-year follow-up. The rates of reversion, progression and mortality were higher in the first 6-year than in the second 6-year follow-up, albeit not statistically significant. Lower systolic blood pressure (SBP), absence of heart diseases and weight loss promoted the reversion from prediabetes to normoglycaemia, whilst obesity accelerated its progression to diabetes.

CONCLUSIONS: During a 12-year follow-up, most of older adults with prediabetes remained stable or reverted to normoglycaemia, whereas only one-third developed diabetes or died. Lower SBP, no heart diseases and weight management may promote reversion to normoglycaemia, suggesting possible strategies for achieving normoglycaemia in older adults with prediabetes.