A cohort analysis of type 1 diabetes mortality in Havana and Allegheny County, Pittsburgh, PA

OBJECTIVE

To examine the mortality of type 1 diabetes (T1D) in two countries with very different health care systems using two population-based registries of childhood-onset T1D one in Havana (HA), Cuba, and the other in Allegheny County (AC), USA.

RESEARCH DESIGN AND METHODS

Cases diagnosed with T1D between 1965 and 1980 in HA and between 1965 and 1979 in AC were included. Follow-up started with diagnosis in each individual and ended as of 1 January 1991, or with death. Life-table analyses were used to examine the mortality rates in both populations by duration of diabetes.

RESULTS

Cumulative mortality by January 1991 in HA (14% in males and females, respectively) was higher than in AC (7% in males and 9% in females) for both genders (males, p=0.0005; females, p=0.0491). Mortality rates were considerably higher in HA for both men and women than in AC however, among females confidence intervals overlapped. Overall mortality rate for Caucasians (AC) was significantly lower than that for African-Americans (AC) or Hispanics (HR). An analysis of causes of death showed a greater proportion of deaths attributed to nephropathy (48.6%) in HA while acute complications (36%) and infections (27%) were more frequent in AC.

CONCLUSIONS

This study shows a two-fold greater mortality among people with childhood-onset T1D in Havana, Cuba, than in Allegheny, USA. Different strategies may be needed to increase survival among those with type 1 diabetes in the USA and Cuba.

Excess mortality in Black compared with White patients with Type 1 diabetes: an examination of underlying causes

AIMS

Excess mortality in Type 1 diabetes has previously been found among Black individuals. The aim of the present study was therefore to determine underlying causes.

METHODS

A longitudinal study of 1261 [1184 White (93.9%) and 76 Black (6.0%)] individuals diagnosed with Type 1 diabetes between 1965 and 1979, at age<17 years from the Allegheny County, Pennsylvania and Children's Hospital of Pittsburgh registries. Subjects were contacted in 1999 to determine living status and, where appropriate, cause of death. Living status was determined in 1183 participants (93.8%).

RESULTS

Of the 200 deaths overall, cause of death was determined in 157 subjects (79%); 31 dying from acute and 101 from chronic complications, and 25 from non-diabetes related causes. Seven deaths were investigated but no cause determined. Black participants had a significantly higher mortality rate compared with White participants for acute complications (hazard ratio=4.9, 95% confidence interval: 2.0, 11.6), but not for any other cause. There was a temporal decline in the 20-year mortality rates in both racial groups across the three cohorts diagnosed in 1965-69, 1970-74 and 1975-79.

CONCLUSIONS

These results show that the excess mortality in Black people was attributed to acute complications which therefore should be a focus for prevention.

Do plasminogen activator inhibitor (PAI-1) or tissue plasminogen activator PAI-1 complexes predict complications in Type 1 diabetes: the Pittsburgh Epidemiology of Diabetes Complications Study

AIMS

To examine the predictive power of plasminogen activator inhibitor-1 (PAI-1) and the complexes it forms with tissue plasminogen activator (tPA-PAI-1) for the two major Type 1 diabetes (T1D) complications (coronary artery disease (CAD) and overt nephropathy) in the context of standard risk factors.

METHODS

Observational prospective study of 454 participants with childhood onset (< 17 years) T1D, aged 18+ years at baseline. PAI-1 and tPA-PAI-1 were determined using ELISA methodology. Follow-up (6 years) was limited to 382 individuals for CAD and 294 individuals for overt nephropathy, after excluding baseline cases. Total, HDL and LDL-cholesterol, triglycerides, HbA1, blood pressure, body mass index (BMI), waist-hip ratio (WHR), leucocyte count, Beck depression score and fibrinogen were also examined.

RESULTS

The 56 incident cases of CAD had marginally lower PAI-1 and higher tPA-PAI-1 levels compared with those free of CAD. However, marginally higher PAI-1 and significantly higher tPA-PAI-1 (P = 0.04) levels were seen in those who developed nephropathy. After controlling for age, both PAI-1 and tPA-PAI-1 showed significant negative correlations with HDL-cholesterol, and positive correlations with triglycerides, WHR, HbA1 and fibrinogen. tPA-PAI-1 was also positively correlated with total and LDL-cholesterol. In multivariate analyses, neither PAI-1 nor tPA-PAI-1 was an independent predictor of CAD or overt nephropathy.

CONCLUSIONS

These results suggest little association between PAI-1 and later CAD in patients with T1D. However, tPA-PAI-1 complexes may be involved in the pathogenesis of overt nephropathy.