Peter Bennett

Despite its growing prevalence in China, the extent to which diabetes leads to excess cardiovascular disease (CVD) mortality and all-cause mortality is unclear. We compared death rates and causes of death among 630 people with newly diagnosed diabetes (NDD) and 519 with normal glucose tolerance (NGT) who, in 1986, were identified as a result of screening 110,660 adults aged 25-74 years for diabetes in Da Qing, China. During 23 years of follow-up, 338 (56.5%) participants with NDD and 100 (20.3%) with NGT died. CVD was the predominant cause of death in those with diabetes (47.5% in men and 49.7% in women), almost half of which was due to stroke (52.3% in men and 42.3% in women). The age-standardized incidence of all-cause death was three times as high in those with NDD as in those with NGT with incidences (per 1,000 person-years) of 36.9 (95% CI 31.5-42.3) vs. 13.3 (10.2-16.5) in men (P < 0.0001) and 27.1 (22.9-31.4) vs. 9.2 (7.8-10.6) in women (P < 0.0001). The incidence of CV...

The metabolic characteristics of type 2 diabetes, insulin resistance, and diminished insulin secretion are costly to measure directly. To evaluate the utility of several simple indices derived from insulin and glucose measurements, the indices were examined from 1982 to 1997 with respect to correlation with more sophisticated measures of insulin sensitivity and secretion in Pima Indians in the Gila River Indian Community of Arizona. Ability to predict the incidence of diabetes in 1,731 persons was also examined. Indices were calculated from fasting and 2-hour glucose (G0, G120) and insulin (I0, I120) concentrations obtained during an oral glucose tolerance test. Fasting serum insulin concentration and the insulin sensitivity index (10(4)/(I0 x G0)) each showed a moderate correlation with the estimate of insulin sensitivity derived from the hyperinsulinemic-euglycemic clamp (absolute value r approximately 0.60). They also strongly predicted the incidence of diabetes (incidence rate r...

Non-insulin-dependent diabetes mellitus (NIDDM) is a major cause of end-stage renal disease. However, the course and determinants of renal failure in this type of diabetes have not been clearly defined. We studied glomerular function at intervals of 6 to 12 months for 4 years in 194 Pima Indians selected to represent different stages in the development and progression of diabetic renal disease. Initially, 31 subjects had normal glucose tolerance, 29 had impaired glucose tolerance, 30 had newly diagnosed diabetes, and 104 had had diabetes for five years or more; of these 104, 20 had normal albumin excretion, 50 had microalbuminuria, and 34 had macroalbuminuria. The glomerular filtration rate, renal plasma flow, urinary albumin excretion, and blood pressure were measured at each examination. Initially, the mean (+/-SE) glomerular filtration rate was 143+/-7 ml per minute in subjects with newly diagnosed diabetes, 155+/-7 ml per minute in those with microalbuminuria, and 124+/-7 ml per minute in those with macroalbuminuria; these values were 16 percent, 26 percent, and 1 percent higher, respectively, than in the subjects with normal glucose tolerance (123+/-4 ml per minute). During four years of follow-up, the glomerular filtration rate increased by 18 percent in the subjects who initially had newly diagnosed diabetes (P=0.008); the rate declined by 3 percent in those with microalbuminuria at base line (P=0.29) and by 35 percent in those with macroalbuminuria (P<0.001). Higher base-line blood pressure predicted increasing urinary albumin excretion (P=0.006), and higher base-line urinary albumin excretion predicted a decline in the glomerular filtration rate (P<0.001). The initial glomerular filtration rate did not predict worsening albuminuria. The glomerular filtration rate is elevated at the onset of NIDDM and remains so while normal albumin excretion or microalbuminuria persists. It declines progressively after the development of macroalbuminuria.

Many risk factors for non-insulin-dependent diabetes mellitus (NIDDM), such as obesity, physical inactivity, and high-fat diet, can potentially be modified. Furthermore, some of the metabolic abnormalities, such as insulin resistance and impaired glucose tolerance, that predict diabetes can be improved by behavior modification and drug treatment. Thus, at least to some extent, NIDDM may be preventable. Several small clinical trials have addressed the hypothesis that NIDDM can be prevented by dietary modification, physical activity, or drug treatment. Some studies suggest a preventive effect, but the conclusions are limited by considerations of sample size, randomization, or intensity of the interventions. Consequently, the hypothesis that NIDDM is preventable requires further testing.

The relationships of rate of weight gain and weight fluctuation to incidence of non-insulin-dependent diabetes mellitus (NIDDM) were examined in Pima Indians. The 1,458 subjects were participants in a prospective study with examinations approximately every 2 years. Rate of weight gain was defined as the slope of the regression line of weight with time for two or more consecutive examinations > or = 2 years apart and weight fluctuation as the root-mean-square departure from this line for four examinations. Among men, incidence of NIDDM was strongly and significantly related to rate of weight gain (e.g., age-adjusted incidence = 56.7/1,000 person-years in those with weight gain > or = 3 kg/year and 16.9/1,000 person-years for those losing weight [Ptrend < 0.01]). In women, weight gain was significantly related to diabetes incidence only in those who were not initially overweight (body mass index < 27.3 kg/m2). In contrast to the relationship with weight gain, weight fluctuation was not associated with incidence of diabetes in either sex. These findings suggest that weight control in overweight individuals may be a more effective strategy for prevention of NIDDM in men than in women, whereas prevention of obesity may prevent diabetes in both sexes. Concern about a diabetogenic effect of weight fluctuation should not deter weight-control efforts.

All individuals with diabetes mellitus should be screened yearly with a spot urine albumin:creatinine ratio to identify those who are at increased risk for the development of complications of diabetes mellitus, including nephropathy, retinopathy, and cardiovascular disease. Once these high-risk individuals are appropriately identified, it is recommended that therapy with an angiotensin-converting enzyme (ACE) inhibitor be initiated. In addition, cardiovascular risk factors should be investigated, and when appropriate, therapeutic interventions should be initiated according to existing recommendations.