Functional status before and after diagnosis of Type 2 diabetes.

AIMS: We examined functional health status prior to the diagnosis of Type 2 diabetes, and measured the effect on functional health status of receiving the diagnosis. METHODS: After the ADA reduced its fasting plasma glucose level for diagnosing diabetes from > 7.8 to > 7.0 mmol/l, we identified 1014 members of a large HMO who met the new criteria, and an age- and gender-matched comparison group who did not. We mailed questionnaires to these subjects in 1998, and again in 1999 to 623 who met the new criteria, after some had been notified of their diabetes, while others had not. We used the SF-12(R) Health Survey to measure physical and mental subjective health status. RESULTS: Mean age of respondents meeting new diagnostic criteria (n = 498) was 67.3 + 10.4 years, 43.6% were women. Comparison group respondents (n = 589) were 66.7 + 10.6 years, 45.2% women. The groups were not statistically different on either characteristic. Prior to the diagnosis of Type 2 diabetes, physical functioning was already lower in subjects who met the new criteria than in the comparison group (39.5 vs. 42.1, P < 0.001), mental functioning was similar (51.4 vs. 51.9, P = 0.406). Among those who newly met diagnostic criteria for diabetes, there was no difference in the change in health status (mental or physical) in those who reported receiving a diagnosis (n = 105) compared with those who did not (n = 168). CONCLUSIONS: Physical health status is already reduced prior to diabetes diagnosis, perhaps because of obesity or other aspects of the insulin resistance syndrome. Receiving a diabetes diagnosis after adjusting the diagnostic criteria does not adversely affect either mental or physical health status.