Economic assessment of troglitazone as an adjunct to sulfonylurea therapy in the treatment of type 2 diabetes

OBJECTIVE

To assess the economic efficiency of adding troglitazone to sulfonylurea therapy to improve glycemic control.

BACKGROUND

Despite the high prevalence of type 2 diabetes, existing treatment strategies often fail. New oral agents give a wider segment of the population with type 2 diabetes hope of achieving near-normal blood-glucose levels. Troglitazone, a novel chemical entity, is one promising new agent.

METHODS

We conducted an economic analysis based on glycemic-control data from a randomized clinical trial comparing troglitazone with placebo, each added to glyburide. A patient simulation model was used to translate these data to long-term outcomes associated with diabetes. Patients had poorly controlled type 2 diabetes mellitus despite glyburide therapy. Risk functions of developing and progressing through nephropathy, retinopathy, neuropathy, hypoglycemia, and macrovascular disease were developed from the Diabetes Control and Complications Trial and large epidemiologic studies. Cost estimates were based on data from 5 states, all payor databases, surveys, and literature. The main outcomes of the model were cost-consequences, number of patients developing each type of complication, mean time to development of the complication, cost per life-year gained (LYG), and cost per quality-adjusted life-year.

RESULTS

The model predicts that for every 1000 patients treated with troglitazone, the improved glycemic control could mean that 95 to 140 fewer patients would experience one of the most severe diabetic complications (eg, blindness, end-stage renal disease, amputation), which may increase life expectancy by 2.0 years. These benefits are obtained at an additional $2100 per LYG (undiscounted). The ratio remains <$50,000 per LYG for most variations in input.

CONCLUSIONS

The clinical trial demonstrated that troglitazone + glyburide improves glycemic control compared with glyburide alone. Based on these results, the model estimates fewer diabetic complications at a cost well below accepted cost-effective thresholds.

Complex relation between increasing fat mass and decreasing high density lipoprotein cholesterol levels: evidence from a population-based study of premenopausal women

High density lipoprotein (HDL) cholesterol levels can be used to predict cardiovascular disease risk in women. To better understand variability in HDL cholesterol levels, the authors examined the relation with three domains (body size and type, sex hormone status, and carbohydrate metabolism) in a cross-sectional population-based 1993-1994 study of 402 premenopausal women from Tecumseh, Michigan. They found that these domains explained 27% of the total variation in HDL cholesterol levels; waist-to-hip ratio was the term that explained the highest proportion of variability (6% after fat mass, sex hormone binding globulin, and insulin levels were added to the model). In analyses restricted to women whose body mass index was > or = 32 kg/m2, which constituted 19% of this population, neither body mass index nor fat mass was a significant predictor of variability in HDL cholesterol levels. Significant variables were insulin levels, waist-to-hip ratio, and smoking. This finding suggests that there is a saturation of the relation between increasing fat mass and lower HDL cholesterol levels, as evidenced by the lack of a relation between the two among the heaviest women. Meanwhile, among the heaviest women, increasing insulin levels and a higher waist-to-hip ratio remained predictors of low levels of HDL cholesterol.

Examination of baseline levels of carboxypeptidase N and complement components as potential predictors of angioedema associated with the use of an angiotensin-converting enzyme inhibitor

OBJECTIVE

To determine if mean levels of complement components and carboxypeptidase N differed when comparing patients who exhibited angioedema following angiotensin-converting enzyme inhibitor therapy to those who received angiotensin-converting enzyme inhibitor therapy but did not have angioedema.

DESIGN

Case-control study nested within an 8-week, open-label study of the use of quinapril hydrochloride for hypertension in 12275 patients.

SETTING

Multicenter, with sites throughout the United States.

PATIENTS

Of the 36 patients with angioedema described, 22 participated in the study. They were matched to 48 controls by age, sex, race, length of follow-up, and geographical region.

INTERVENTION

All patients received quinapril therapy prior to participation in this case-control study.

MAIN OUTCOME MEASURES

Levels of carboxypeptidase N, total hemolytic complement, C1 esterase inhibitor, and C4, along with questionnaire data, including a history of angioedema-like episodes and family history of angioedema.

RESULTS

The 22 patients had significantly lower mean levels of carboxypeptidase N (kininase I) (P = .03) and C1 esterase inhibitor (P = .04) compared with the 48 matched controls, but all mean values were within normal laboratory ranges. A history of prior angioedema-like episodes was associated with an approximate 6-fold increase in the subsequent risk of angioedema following angiotensin-converting enzyme inhibitor therapy.

CONCLUSIONS

Small differences in levels of carboxypeptidase N or C1 esterase inhibitor may contribute to an increased risk of angioedema with angiotensin-converting enzyme inhibitor therapy. Given the large overlap in the distributions of carboxypeptidase N and C1 esterase inhibitor levels, prior testing could not be used to evaluate angioedema risk for an individual patient considering angiotensin-converting enzyme inhibitor therapy. A history of prior angioedema-like episodes was associated with increased risk, but this result should be interpreted with caution because of possible recall bias.

Cause of death in Alzheimer's disease

Cause of death among 917 of the 959 subjects in a population-based incidence cohort with Alzheimer's disease (AD) during the years 1960 to 1984 was compared to that of an age- and gender-matched control group (n = 703). In general, a summary of the diagnostic codes entered anywhere on a death certificate suggests that control subjects had more cardiovascular disease and neoplasms than did patients, while patients more often had a diagnostic code of bronchitis/pneumonia (P < 0.01). By logistic regression, this difference remained statistically significant after adjusting for age and gender.

Pulmonary toxicity of cyclophosphamide: a 1-year study

The development of cyclophosphamide-induced pulmonary lesions over a 1-year period was studied in mice. Male BALB/c mice received a single intraperitoneal injection of 100 mg/kg of cyclophosphamide. Within 3 weeks there were scattered foci of intraalveolar foamy macrophages. With time, these foci increased in size and, 1 year later, occupied large areas in all lung lobes. There was also diffuse interstitial fibrosis. Chemical determination done 3, 12, 24, and 52 weeks after cyclophosphamide showed that lungs of animals treated with cyclophosphamide had significantly more hydroxyproline per lung than controls. One year after cyclophosphamide pressure-volume curves measured in vivo were shifted down and to the right and total lung volumes were decreased. A single injection of cyclophosphamide produced an irreversible and progressive pulmonary lesion.