Habitual physical activity and glucose tolerance. Males age 16-64 in a total community.

The data being reported are part of an epidemiologic study of health and disease in an entire community, Tecumseh, Michigan. Approximately 1,300 males age 16-65 were classified into three groups on the basis of their habitual leisure and occupational physical activity. A blood sample was drawn one hour after a glucose challenge and analyzed for glucose concentration. A measure of body fatness (sun of four skinfolds) was also available on the men. Glucose concentration of the three physical activity groups was compared by analyses of variance within narrow age group. There was no significant relationship between glucose tolerance and habitual physical activity. There was a slight, but in some age groups significant, relationship between glucose tolerance and body fatness. The population was then divided within each age group into subgroups (thirds) by sum of skinfolds. The analysis was repeated in each age-fatness group. Glucose tolerance was better in the active men but only among the leanest subgroup of subjects.

Diabetes among men in a general population. Prevalence and associated physiological findings.

A random sample of 281 men, aged 30 through 69, resident in the community of Tecumseh, Mich, was studied with the use of standard glucose tolerance tests, including serum insulin assays and fasting serum lipid concentrations. Diagnoses of diabetes and probable diabetes were made according to a modification of the criteria of Fajans and Conn. Prevalence of diabetes and probable diabetes was considerably higher among men aged 40 through 49 than among those aged 30 through 39, but it increased little in the 50-through-59 and 60-through-69 age groups. Lean nondiabetics and probable diabetics had similar mean systolic blood pressures and similar mean levels of serum cholesterol, serum triglycerides, and serum insulin, but fat probable diabetics had much higher mean serum lipid and serum insulin concentrations that fat nondiabetics. Adiposity grouping discriminated by variable levels less well between diabetics and nondiabetics.

Physiological variables and diabetic status. Findings in Tecumseh, Mich.

A random sample of 568 participants in the Tecumseh, Mich, study, aged 30 to 59 years, was stratified according to blood glucose concentration to select a high proportion of diabetics. Subjects were categorized as overt diabetics, chemical or probable diabetics, or nondiabetics. Diabetic groups and nondiabetics were compared for levels of blood glucose, plasma insulin, serum cholesterol, serum triglyceride, blood pressure, and contours of glucose and insulin curves. Overt diabetics had high mean fasting blood glucose levels. Challenged diabetics had significantly higher concentrations of all variables except cholesterol than nondiabetics, even after adjustment for age and adiposity. Glucose intolerance, adiposity, and sex influenced variables independently. Risk of atherosclerosis is partly attributable to persistent hyperglycemia and related metabolic abnormalities in overt diabetics. Postchallenge diabetics have subtle hyperglycemia but a high frequency of other risk factors. Recent developments suggest that control of blood glucose may become feasible and useful in the prevention of cardiovascular disease in overt and challenged diabetics.

Type IV hyperlipoproteinemia: effects of a caloric restricted type IV diet versus physical training plus isocaloric type IV diet.

Serum lipids, plasma insulin and glucagon, aerobic capacity, and body composition were examined in middle-aged men (X age = 44.2 years) with type IV hyperlipoproteinemia to determine the relative effectiveness of a caloric restricted type IV hyperlipoproteinemia diet (group A) versus physical training plus an isocaloric type IV diet (group B). After 9 weeks of the above interventions, reductions (P less than 0.01) in mean cholesterol levels from 213 to 186 (12% change) and from 205 to 185 mg/dl (9% change), and in triglyceride levels from 332 to 211 (29% change) and from 263 to 138 mg/dl (42% change) were found for groups A and B, respectively. A small reduction in mean fasting insulin level was found only in group B; this reduction appeared inversely associated with increases in aerobic capacity in group B (r = -0.66). Both interventions were without effect on fasting glucagon levels. The physical training program prescribed resulted in a 12% increase in aerobic capacity (group B). Significant mean body weight reductions of 7.7 lb (P less than 0.01) and 2.9 lb (P less than 0.01) were seen for groups A and B, respectively; these absolute body weight reductions differed significantly (P less than 0.05) between groups. Both groups significantly lost body fatness (P less than 0.01). These reductions in body weight and body fatness appeared independent of changes in lipid levels. These results demonstrate that both interventions reduce serum lipids in men with type IV hyperlipoproteinemia but that physical training plus an isocaloric type IV diet may be the more advantageous of the two regimens, since a greater percentage decrease and a more sustained reduction in serum triglyceride levels, and a greater reduction of fasting hyperinsulinemia were observed in group B.

Comparative effects of overweight on cardiovascular risk in younger versus older men.

The relation of age and body mass index (BMI) to atherosclerosis risk factors was examined in 357 men. Older (greater than or equal to 45 years) men had higher (p less than 0.01) systolic and diastolic blood pressures, fasting cholesterol and glucose, and 1-hour glucose and insulin levels. Fasting insulin and triglyceride levels were not significantly different between the 2 age groups. Although older men (n = 170) had greater values for several risk factors, overweight (BMI greater than 25.5 kg/m2) increased risk factors more in men younger than 45 years (n = 187). In younger men, those with higher BMIs had a greater prevalence, respectively, of blood pressure greater than 140/90 mm Hg (35.2 vs 11.2%, p less than 0.0001), cholesterol greater than 200 mg/dl (53.5 vs 29.3%, p less than 0.001), fasting triglycerides greater than 150 mg/dl (38.0 vs 10.3%, p less than 0.0001), 1-hour glucose greater than 160 mg/dl (15.5 vs 5.2%, p less than 0.05), fasting insulin greater than 11 microU/ml (28.2 vs 5.2%, p less than 0.0001), and 1-hour insulin greater than 110 microU/ml (28.2 vs 9.5%, p less than 0.001). In contrast, among older men, the prevalence of elevated blood pressure, cholesterol, triglycerides and glucose values was not significantly greater in the subgroup with high BMI. However, elevations of fasting (19.6 vs 6.4%, p less than 0.05) and 1-hour insulin (29.3 vs 11.5%, p less than 0.01) values were more common among older men with higher BMIs.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolic adaptation with physical training: 14C-acetate incorporation into tissue lipids.

Forty-eight rats were fed ad libitum, fasted 24 hr, rested 48 hr,and injected i.p. with 40 muCi of 14C-acetate/100 g body weight. Twenty-four rats had followed a progressive physical training program for 12 wk and 24 rats acted as their controls. Following this injection, the rats were sequentially sacrificed at 5-, 10-, 15-, and 20-min intervals and total cholesterol (TC), free cholesterol (FC), and triglyceride (TG) specific activity and concentrations were measured from serum, liver, triceps, and heart tissue. Curves relating specific activity to the time point data were fitted by the method of least squares. Comparison of these curves revealed that serum, liver, and triceps TC and FC specific activity were significantly higher in the trained rats. In contrast, corresponding TC and FC concentrations for these three tissues varied. Liver TC level was significantly less for the trained group, probably due to a reduction in the esterified moiety, since liver FC measures were unchanged. Training resulted in significantly lower TC concentrations in the selected tissues studied even though specific activity curves appeared similar for both groups. Our conclusions are that lipid metabolic adaptation; studied in vivo, occurs in tissues with training, but that these adaptations are not uniform across tissues, lipid moieties, or measurement parameters.

Effect of exercise training on glucose tolerance, in vivo insulin sensitivity, lipid and lipoprotein concentrations in middle-aged men with mild hypertriglyceridemia.

The effects of 9 weeks of aerobic exercise training with maintenance of stable body weight upon insulin sensitivity and upon glucose, lipid, and lipoprotein concentrations were studied in 10 middle-aged men with mild hypertriglyceridemia. Following training, mean maximum oxygen consumption improved from 33.5 +/- 1.9 to 39.3 +/- 1.9 mL/kg/min (means +/- SEM), (P less than 0.01). Glucose concentrations, both fasting and during oral glucose tolerance testing, remained stable but both fasting insulin concentrations and insulin responses to oral glucose decreased (P less than 0.1 and less than 0.01, respectively). In vivo insulin sensitivity improved 25 +/- 6.1% (P less than 0.01) following training. Exercise training resulted in decreases in fasting serum triglyceride concentrations from 203 +/- 12.6 to 126 +/- 9.0 mg/dL (P less than 0.01), primarily as a result of the reduction in VLDL-triglycerides (P less than 0.01). The magnitude in percentage decrease of VLDL-triglycerides was found to be significantly correlated (r = 0.71, P less than 0.05) with the magnitude in percent increase in max VO2. Serum cholesterol levels declined from 211 +/- 8.9 to 193 +/- 11.9 mg/dL (P less than 0.01), and the ratio of HDL-cholesterol to total cholesterol was improved. This study demonstrates that exercise training at a level of intensity feasible for many middle-aged men has beneficial effects on several factors that have been associated with an increased risk of cardiovascular disease.

Effects of exercise training on plasma lipids and lipoproteins in rats.

We studied the effects of exercise training on plasma lipid and lipoprotein concentrations of rats on a high-fat and high-cholesterol diet. Twelve weeks of training occurred at moderate [Mod-Exer, 70% peak O2 consumption (VO2)] and high (High-Exer, 82% peak VO2) intensities. The duration of daily training sessions was adjusted to maintain equivalent energy expenditure between groups. Following training, body weight and lean body mass were 10% lower in the High-Exer group than the Mod-Exer or control groups. Compared with control values, carcass fat content was 33% lower for both trained groups. The oxidative capacity of skeletal muscle was approximately 30% greater in the trained groups compared with the control group. Total cholesterol, high density lipoprotein cholesterol, and total triglyceride concentrations in plasma were not different between the trained groups, but were 33-47% lower compared with the control group. The exercise-induced changes in plasma lipid and lipoprotein concentrations may be a result of a change in preferred substrate utilization in skeletal muscle toward a greater oxidation of lipid.

Sensory responses, dietary-induced obesity and biochemical values in Sprague-Dawley rats.

Food intake and body weight gain variability in Sprague-Dawley (SD) rats exposed to a palatable high-fat diet were examined in relation to sensory responses and biochemical parameters in two experiments. In the first experiment, varying sucrose concentrations (4-32% wt./vol.) were randomly presented for 20 minutes to ad lib chow-fed rats. Each rat's sensory response was expressed as Beta (B), or the slope of the regression between solute intake and concentration, and used to assign rats to diet groups. In the second experiment, responsiveness to fat emulsions (1-37%) were similarly measured and categorized. In both experiments sensory responses to sucrose were significantly related to weight gain/fatness on the high-fat diet (lab chow-corn oil). Sensory responsiveness to the fat emulsions was unrelated to sucrose responsiveness or to high-fat feeding. Biochemical parameters (insulin, cholesterol, triglycerides, lipoproteins) reflected increased caloric (fat) intake, as well as sucrose responsiveness. Predictors (sensory responses, biochemical values) of response to chronic (4 months) or short-term (less than 2 months) high-fat diets are discussed.

Nutritional indexes of clients in a maternity and infant care project. I. The target population.

The Detroit Maternity and Infant Care Project (DMICP) is funded under Title V of the Social Security Act. Records of 198 pregnant women and their infants seen by a project nutritionist in fiscal 1971-72 were studied. The women were predominantly young (below twenty years of age), black, and not enrolled in school. Most were pregnant for the first time. About a third were overweight. Mean scores on the APGAR scale for the infants at birth were high (7 to 10). More than half of these young mothers brought their infants to the project center for check-ups six to ten times during the first year.

Nutritional indexes of clients in a maternity and infant care project. II. Dietary, anthropometric, and hematologic indexes of pregnant women and their infants.

Low intakes by 198 pregnant women of milk, fruit, and vegetables are reported: consumption of meat and bread and cereals was satisfactory. However, mean hemoglobin and hematocrit values were within acceptable ranges for these women, indicating that supplementation apparently compensated in part for poor dietary habits. Protein intake of the infants of these mothers was above recommendations, the advisability of which is questioned. Height and weight of the male and female infants at birth were above and below the 10th percentile, respectively. By the age of four months, however, all infants were equal to or above this level. Mean hemoglobin levels were above acceptable levels.

Nutritional indexes of clients in a maternity and infant care project. III. Relationships between developmental, medical, and nutritional variables.

Nutritional and medical records of the infants of 198 women of a low socioeconomic group were correlated with results of the Denver Developmental Screening Test. At one year, the infants' developmental age was above the norm. In addition, selected medical, nutritional, and developmental variables, as indicated by charts of the Detroit Maternity and Infant Care Project, were statistically analyzed for interrelationships. No correlation was found between hemoglobin levels, even though they were low for some infants, and developmental indexes. Prenatal weight gain of the mothers was statistically significant in relation to their infants' birth weight, height, and head circumference. Thus periodic monitoring of weight throughout pregnancy is recommended.