New classification and criteria for diabetes: moving the goalposts closer

How many patients with coronary heart disease are not achieving their risk-factor targets? Experience in Victoria 1996-1998 versus 1999-2000

OBJECTIVES

To determine the proportion of patients with established coronary heart disease (CHD) in two Australian studies (VIC-I in 1996-1998, and VIC-II in 1999-2000) who achieved their risk-factor targets as recommended by the National Heart Foundation of Australia, and to compare this proportion with those in studies from the United Kingdom (ASPIRE), Europe (EUROASPIRE I and II) and the United States (L-TAP).

DESIGN AND SETTING

Prospective cohort study with VIC-I set in a single Melbourne university teaching hospital and VIC-II set in six university teaching hospitals in Melbourne, Victoria.

PARTICIPANTS

460 patients (112 in VIC-I, 348 in VIC-II) who completed follow-up in the control groups of two randomised controlled trials of a coaching intervention in patients with established CHD.

MAIN OUTCOME MEASURES

The treatment gap (100%, minus the percentage of patients achieving the target level for a particular modifiable risk factor) at six months after hospitalisation.

RESULTS

The treatment gap declined from 96.4% (95% CI, 91%-99%) to 74.1% (95% CI, 69%-79%) for total cholesterol concentration (TC) < 4.0 mmol/L (P = 0.0001) and from 90.2% (95% CI, 83%-95%) to 54.0% (95% CI, 49%-59%) for TC < 4.5 mmol/L (P = 0.0001). This reduction in the treatment gap between VIC-I and VIC-II appears to be entirely explained by an increase in the number of patients prescribed lipid-lowering drugs. The treatment gaps in the UK and two European studies were substantially greater. The treatment gap for blood pressure (systolic > or = 140 mmHg and/or diastolic > or = 90 mmHg) in VIC-II was 39.5%, again less than corresponding European data. There were 8.1% of patients who had unrecognised diabetes in VIC-II (fasting glucose level > or = 7 mmol/L), making a total of 25.6% of VIC-II patients with diabetes, self-reported or unrecognised. The proportion of patients in VIC-II who were obese (body mass index > or = 30 kg/m2) was similar to the overseas studies, while fewer patients in VIC-II smoked compared with those in the UK and European studies.

CONCLUSIONS

A substantial treatment gap exists in Victorian patients with established CHD. The treatment gap compares well with international surveys and, at least in the lipid area, is diminishing.

All-cause mortality in the Canterbury (New Zealand) insulin-treated Diabetic Registry population

OBJECTIVE

To establish all-cause death rates and life expectancies of and risk factors for mortality in insulin-treated diabetic individuals living in Canterbury, New Zealand.

RESEARCH DESIGN AND METHODS

Insulin-treated diabetic subjects (n = 1,008) on the Canterbury Diabetes Registry were tracked over 9 years, and their vital status was determined. Death rates were standardized using direct and indirect methods. Cox proportional hazard regression was used to model the effects of demographic and clinical covariates on survival time.

RESULTS

At study entry, age ranged from 2.9 to 92.7 years, with mean 48.7 +/- 20.4 years; age at diagnosis was 0.2-88.9 years, mean 34.5 +/- 20.0 years; and duration of diabetes was 0.1-58.5 years, mean 14.0 +/- 10.6 years. There were 303 deaths in 7,372 person-years of follow-up with a standardized mortality ratio (SMR) of 2.6 (95% CI 2.4-3.0). Relative mortality was greatest for those aged 30-39 years (SMR 9.2 [4.8-16.2]). The death rate for the diabetic cohort standardized against the Segi world standard population was 16.2 per 1,000. Attained age, sex, and clinical subtype were significant predictors of mortality The SMR for subjects with type 1 diabetes and age at onset <30 years was 3.7 (CI 2.7-5.0), 2.2 (1.8-2.6) for those with onset > or =30 years, and 3.1 (2.5-3.7) for subjects suspected of having latent autoimmune diabetes in adulthood or insulin-treated type 2 diabetes. Life expectancy was reduced for both sexes at all ages.

CONCLUSIONS

Mortality rates for insulin-treated diabetic individuals remain high, resulting in shortened life spans relative to the general population. Marked differences in mortality exist between clinical groups of subjects. Further research is needed to improve diabetes classification and to clarify differences in health outcomes.