The Legacy Effect in Type 2 Diabetes: Impact of Early Glycemic Control on Future Complications (The Diabetes & Aging Study)

Diabetes Care. 2019 Mar;42(3):416-426. doi: 10.2337/dc17-1144. Epub 2018 Aug 13.

Abstract

Objective: To examine for a legacy effect of early glycemic control on diabetic complications and death.

Research design and methods: This cohort study of managed care patients with newly diagnosed type 2 diabetes and 10 years of survival (1997-2013, average follow-up 13.0 years, N = 34,737) examined associations between HbA1c <6.5% (<48 mmol/mol), 6.5% to <7.0% (48 to <53 mmol/mol), 7.0% to <8.0% (53 to <64 mmol/mol), 8.0% to <9.0% (64 to <75 mmol/mol), or ≥9.0% (≥75 mmol/mol) for various periods of early exposure (0-1, 0-2, 0-3, 0-4, 0-5, 0-6, and 0-7 years) and incident future microvascular (end-stage renal disease, advanced eye disease, amputation) and macrovascular (stroke, heart disease/failure, vascular disease) events and death, adjusting for demographics, risk factors, comorbidities, and later HbA1c.

Results: Compared with HbA1c <6.5% (<48 mmol/mol) for the 0-to-1-year early exposure period, HbA1c levels ≥6.5% (≥48 mmol/mol) were associated with increased microvascular and macrovascular events (e.g., HbA1c 6.5% to <7.0% [48 to <53 mmol/mol] microvascular: hazard ratio 1.204 [95% CI 1.063-1.365]), and HbA1c levels ≥7.0% (≥53 mmol/mol) were associated with increased mortality (e.g., HbA1c 7.0% to <8.0% [53 to <64 mmol/mol]: 1.290 [1.104-1.507]). Longer periods of exposure to HbA1c levels ≥8.0% (≥64 mmol/mol) were associated with increasing microvascular event and mortality risk.

Conclusions: Among patients with newly diagnosed diabetes and 10 years of survival, HbA1c levels ≥6.5% (≥48 mmol/mol) for the 1st year after diagnosis were associated with worse outcomes. Immediate, intensive treatment for newly diagnosed patients may be necessary to avoid irremediable long-term risk for diabetic complications and mortality.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aging / blood
  • Aging / physiology*
  • Blood Glucose / analysis
  • Blood Glucose / metabolism*
  • Cohort Studies
  • Comorbidity
  • Diabetes Complications / blood
  • Diabetes Complications / epidemiology
  • Diabetes Complications / prevention & control*
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / epidemiology*
  • Diabetes Mellitus, Type 2 / therapy*
  • Disease Progression
  • Early Medical Intervention / methods
  • Early Medical Intervention / statistics & numerical data*
  • Female
  • Follow-Up Studies
  • Glycated Hemoglobin A / analysis
  • Glycated Hemoglobin A / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Risk Factors
  • Survival Analysis
  • Time Factors
  • United States / epidemiology

Substances

  • Blood Glucose
  • Glycated Hemoglobin A