Table 3

HRs (95% CI) for incident cognitive impairment and dementia by baseline cognitive status

Incident cognitive impairment§ among participants dementia-free at baselineIncident dementia among participants with MCI at baseline
n/N (%)Adjusted HR (95% CI)n/N (%)Adjusted HR (95% CI)
Diabetes
 No638/3,344 (19.1)1 (reference)169/639 (26.5)1 (reference)
 Yes390/1,755 (22.2)1.14 (1.00, 1.31)*125/434 (28.8)1.15 (0.90, 1.47)
Diabetes and glycemic control
 No diabetes638/3,344 (19.1)1 (reference)169/639 (26.4)1 (reference)
 Diabetes, HbA1c <7%264/1,276 (20.7)1.05 (0.91, 1.22)81/305 (26.6)1.02 (0.78, 1.35)
 Diabetes, HbA1c ≥7% (compared with no diabetes)119/459 (25.9)1. 38 (1.12, 1.69)**39/122 (32.0)1.38 (0.96, 2.00)
 Diabetes, HbA1c ≥7% (compared with HbA1c<7%)119/459 (25.9)1.31 (1.05, 1.63)*39/122 (32.0)1.35 (0.91, 2.00)
Diabetes duration
 <5 years75/441 (17.0)1 (reference)27/103 (26.2)1 (reference)
 ≥5 years302/1,234 (24.5)1.59 (1.23, 2.07)***95/311 (30.6)1.40 (0.88, 2.20)
  • Models are adjusted for age, race-center, sex, education level, cigarette smoking status (current/former/never), drinking status (current/former/never), APOE e4 (zero, one, or two alleles), hypertension (yes/no), history of stroke (yes/no), and history of CHD (yes/no). Diabetes was defined based on self-reported diagnosis, use of glucose-lowering medication, or HbA1c of ≥6.5% (48 mmol/mol). HbA1c of 7% is equivalent to 53 mmol/mol.

  • †Among persons with diabetes.

  • n/N: the number of incident cases (n) among the total number of participants in that group (N).

  • §Cognitive impairment includes incident MCI in persons cognitively normal at baseline and incident dementia in persons cognitively normal or MCI at baseline.

  • *P < 0.05; **P < 0.01; ***P < 0.001.