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Biomedical subjects

E A Sims

Publications and source records attributed to E A Sims.

At least 19 recordsLinked to original sources
PubMed1992

Longitudinal changes in basal hepatic glucose production and suppression during insulin infusion in normal pregnant women.

OBJECTIVE: The purpose of this study was to evaluate basal endogenous glucose production and suppression during insulin infusion in normal pregnant women. STUDY DESIGN: This prospective, longitudinal study was conducted at the Medical Center Hospital of Vermont. Six healthy women were evaluated before conception and at 12 to 14 and 34 to 36 weeks' gestation. Body composition was estimated by hydrodensitometry. Basal endogenous glucose production was estimated with a primed constant infusion of 6-6 2H2 glucose, and suppression of endogenous glucose production was estimated with insulin infusion during a hyperinsulinemic-euglycemic clamp. RESULTS: There was a significant (p = 0.02) 65% increase in fasting insulin concentration by late gestation. Moreover, there was a significant 30% (p = 0.0005) increase in basal endogenous glucose production (mg/min) with advancing gestation, which remained significant (p = 0.05) when corrected for fat-free mass. During insulin infusion endogenous glucose production was almost completely suppressed (i.e., > 90%) throughout gestation. CONCLUSIONS: There is a significant increase in basal endogenous glucose production at 34 to 36 weeks' gestation in spite of a significant increase in fasting insulin concentration. However, endogenous glucose production remains sensitive to insulin infusion throughout gestation.

Adult↗
PubMed1991

Longitudinal changes in insulin release and insulin resistance in nonobese pregnant women.

To assess the longitudinal changes in insulin release and insulin sensitivity in nonobese normal women during gestation, six women were evaluated with oral glucose tolerance testing, body composition analysis, intravenous glucose tolerance tests, and the hyperinsulinemic-euglycemic clamp before conception, at 12 to 14 weeks, and at 34 to 36 weeks' gestation. There was a significant increase in the insulin/glucose ratio (p = 0.028) during the oral glucose tolerance test during gestation. There was also a significant 3.0- to 3.5-fold increase throughout gestation in first-phase (p = 0.001) and second-phase (p = 0.0001) insulin release during the intravenous glucose tolerance test. Peripheral insulin sensitivity was estimated as the glucose infusion rate (in milligrams per kilogram fat-free mass per minute) during the hyperinsulinemic-euglycemic clamp. There was a significant (p = 0.0003) 56% decrease in insulin sensitivity through 36 weeks' gestation. These results are the first to prospectively evaluate the longitudinal changes in maternal carbohydrate metabolism from the time before conception through late gestation with newer methods such as the hyperinsulinemic-euglycemic clamp.

Administration, Oral↗
PubMed1990

Incidence and significance of islet cell antibodies in women with previous gestational diabetes.

Islet cell antibodies (ICAs) are markers for patients at risk for insulin-dependent diabetes and are associated with progressive beta-cell destruction. This prospective study was performed to estimate the incidence of these antibodies in 187 women with previous gestational diabetes. With a specific protein A monoclonal antibody (MoAb) assay, the incidence of ICAs was only 1.6% (3 of 187). Oral and intravenous glucose tolerance tests were performed in these 3 women and compared with 6 women with previous gestational diabetes without ICAs and 5 control women. Glucose tolerance was impaired only in the 3 women with ICAs, who also had an increase (P less than 0.03) in fasting plasma glucose and a decrease (P less than 0.03) in early first-phase insulin response. We conclude that the more specific MoAb method indicates a lower incidence of ICA in women with a history of gestational diabetes than previously reported and that a decreased first-phase insulin response is associated with the presence of ICAs, suggesting progressive islet cell damage.

Adult↗
PubMed1989

Storage and expenditure of energy in obesity and their implications for management.

We have seen in the past 20 years intensive investigation of the responses of the obese and the lean to caloric intake and to various environmental stresses. Although there is much discrepancy of results, the following are obvious: Obesity is not a clear-cut syndrome, and individuals differ significantly in their genetic subtypes and in the stages, type, and degree of their metabolic disturbances. A difference in the facultative component of the thermogenic effect of food can explain some of the variation. This in turn is closely related to insulin resistance, which bears a close relationship to subtypes of hypertension and hyperlipidemias. The greatest scope for clinical intervention lies in these fields. Both the obese and the lean subjects are adapted to retain dietary fat independently of the energy needs. The high ratio of fat to carbohydrate in the western diet and, increasingly in that of the east, is cause for concern.

Body Temperature Regulation↗
PubMed1987

1987 Herman award lecture. A plea for an integrated approach to characterization and management of obesity, type II diabetes, hyperlipidemias, and hypertension: a role for the personal computer?

In the Vermont study of experimental obesity, heterogeneity of the response to overfeeding was a striking finding in normal subjects. There is also poorly defined heterogeneity within the areas of obesity, noninsulin-dependent diabetes, hyperlipidemias, and so-called essential hypertension. These disorders may occur in the same individual and have important mechanisms in common. Thus it is logical to strive for an integrated approach to nutritional and medical management rather than an approach fragmented between medical specialties. The rapidly developing computer programs now adapted to microcomputers hold promise of facilitating an integrated approach both in the clinical and in the investigative field.

Diabetes Mellitus, Type 2↗
PubMed1986

Subclinical abnormalities of glucose metabolism in subjects with previous gestational diabetes.

To investigate whether there are subclinical abnormalities of glucose metabolism in women with previous gestational diabetes that are consistent with a high incidence of diabetes mellitus in later life, eight patients with previous gestational diabetes and normal oral glucose tolerance were evaluated by means of body composition studies, intravenous glucose tolerance tests, and the hyperinsulinemic-euglycemic clamp coupled with 6-6 dideuterated glucose infusion, indirect calorimetry, and measurement of islet cell antibodies. Eight control subjects were matched for percent body fat and diet and studied in a similar fashion. Abnormalities of insulin response and insulin resistance were present in four (50%) of patients with previous gestational diabetes. Insulin resistance was significantly greater in the patients than in the control subjects. When compared with lean patients, obese patients with previous gestational diabetes had significantly greater insulin response to the intravenous glucose tolerance test and insulin resistance. These changes are consistent with reported findings of an early and progressive development of overt diabetes in patients who had gestational diabetes.

Autoantibodies↗
PubMed1986

Effect of diet on energy expenditure and plasma norepinephrine in lean and obese Pima Indians.

To assess whether thermogenesis or sympathetic nervous system (SNS) function might differ between lean and obese human subjects, studies of thermic and sympathetic responses to standard stimuli were undertaken in Pima Indians, an ethnic group with a high prevalence of obesity. Plasma levels of norepinephrine (NE) and energy expenditure at rest and in response to feeding, exercise, and graded infusions of NE were compared in five lean and five obese Indians during a period of weight maintenance (WM), after 3 weeks of overfeeding (OF) and, in the obese, also after 6 weeks of underfeeding (UF). Basal energy expenditure, when adjusted for fat free mass, was equivalent during WM and increased 3% with OF (P less than 0.01) in both groups. Thermic responses to exercise or a test meal did not differ in lean and obese and did not change with OF, while thermic responses to NE infusion fell during OF to a greater degree in obese than lean (P less than 0.05). A similar pattern (decreased effect in obese with OF) was also noted in the glycemic response to infused NE (P less than 0.05). Although not quantitatively different in lean and obese, the plasma NE concentration appeared to vary more in response to feeding or dietary alteration in the obese than lean, a finding that may reflect lower plasma clearance of NE in the obese. These studies, therefore, raise the possibility that overfeeding in obese Pima Indians may limit the contribution of sympathetically mediated thermogenesis to energy expenditure, though the implications of this for body weight regulation are speculative.

Adolescent↗
PubMed1985

Mood and appetite during minimal-carbohydrate and carbohydrate-supplemented hypocaloric diets.

After a baseline period of free-feeding, 20 obese outpatients alternated between four 2-wk periods of minimal-carbohydrate diet (800 kcal; 58% protein and 42% fat by weight) and of a carbohydrate-supplemented diet (1,000 kcal; 42% protein, 30% fat, and 28% carbohydrate). In a comparison of psychological adjustment during the baseline and low-calorie diets, the initial 2 wk of dieting was associated with a decrease in appetite and elevation of psychological well-being, regardless of the composition of the diet. Thereafter, appetite and mood approached basal levels. Further changes in these psychological reactions to dieting did not vary with the type of diet. There was no support for the idea that a minimal-carbohydrate, protein-supplemented fast decreases appetite and elevates mood more in comparison with a similar diet containing enough carbohydrate to minimize ketosis.

3-Hydroxybutyric Acid↗
PubMed1984

Evidence for an increased risk for hypertension with centrally located body fat and the effect of race and sex on this risk.

Data from the First Health and Nutrition Examination Survey (HANES), 1971-1974, were used to examine the relationship between blood pressure and the distribution of subcutaneous body fat in 5506 survey participants, ages 30-59. Triceps and subscapular skinfolds were used as approximations of peripheral and centrally located body fat. The effects of race, sex and age on the obesity-blood pressure relationship were analyzed. Subscapular skinfold was the better predictor of both systolic and diastolic blood pressure in each race-sex group, sharing all of the association of triceps with blood pressure and having significant predictive power unshared by triceps. The slopes of regression of subscapular skinfolds with systolic blood pressure for each race-sex group were not significantly different. A 1 mm increase in skinfold thickness increased the predicted mean systolic blood pressure by 0.63 +/- 0.03 mmHg (F = 519). Mean diastolic blood pressure rose 0.43 +/- 0.02 mmHg per unit increase of skinfold in whites (F = 549), and 0.14 +/- 0.04 mmHg less in blacks (F = 13), indicating a significant racial difference. Age and subscapular skinfold contributed independently to the variability in blood pressure in each race-sex group. These results demonstrate that the blood pressure of middle-aged Americans is more directly associated with centrally deposited body fat. This finding is true across race and sex groups, and is independent of age.

Adult↗
PubMed1984

Effects of physical training and diet therapy on carbohydrate metabolism in patients with glucose intolerance and non-insulin-dependent diabetes mellitus.

The effects of 12 wk of physical training in addition to hypocaloric diet (DPT group, N = 10) on body composition, carbohydrate (CHO) tolerance, and insulin secretion and action were compared with the effects of diet therapy alone (D group, N = 8) in CHO-intolerant and non-insulin-dependent diabetic subjects. Fat mass, fat-free mass (FFM), mean fasting plasma glucose, serum C-peptide, and insulin concentrations decreased similarly in both groups. The mean plasma glucose response to a mixed meal decreased approximately 20% in both treatment groups, and, after i.v. glucose, decreased 12% in the D group (P less than 0.05), but did not change in the DPT group (NS between groups). The acute serum insulin response (0-6 min) after IG increased significantly in the DPT group only (NS between groups). The mean basal endogenous glucose production (BEGP) decreased 17% (P less than 0.025) in the DPT group and by 31% (P less than 0.01) in the D group (NS between groups). Hepatic sensitivity to insulin, estimated by BEGP suppression during the euglycemic clamp, increased significantly by 25% in both groups. Total glucose disposal during the euglycemic clamp increased from 3.51 +/- 0.04 milligrams of glucose per kilogram of fat-free mass per minute (mg/kg-FFM/min) to 4.45 +/- 0.54 mg/kg-FFM/min (P less than 0.05) in the DPT group, but no change occurred in the D group (NS between groups).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Effects of carbohydrate-containing and carbohydrate-restricted hypocaloric and eucaloric diets on serum concentrations of retinol-binding protein, thyroxine-binding prealbumin and transferrin.

The effects of diet on the serum concentrations of albumin, transferrin, thyroxine-binding prealbumin (TBPA) and retinol-binding protein (RBP) were studied in 3 groups of obese subjects (Groups I-III) and 1 group of normal weight subjects (Group IV). Group I subjects ate either a 830 kcal carbohydrate-containing diet (CCD) or carbohydrate-restricted diet (CRD), Group II and III subjects ate a hypocaloric CRD. Subjects in Group IV ate a eucaloric CRD. Serum albumin concentrations did not change in any of the 4 groups. Only the subjects in Group II had a statistically significant decrease in serum transferrin concentration 6 wk after starting the hypocaloric, CRD. Group I individuals eating the CRD and the subjects in Groups II, III and IV had significant decreases in the serum concentrations of TBPA and RBP after 1 wk which persisted without further change during the remaining 3-5 wk of the diets. Group I subjects eating the CCD had a significant decrease in TBPA concentration at 1 and 6 wk. The RBP serum concentration was significantly decreased after 1 wk on the diet, but was not significantly different from the control diet period at 6 wk. The magnitude of the decreases in serum concentrations of TBPA and RBP in the Group I subjects eating the CRD were significantly greater than in the Group I subjects eating the CCD. Thus, ingestion of a hypocaloric, CRD by obese individuals results in decreased serum concentrations of TBPA and RBP. Isocaloric substitution of carbohydrate for fat reduces this effect. Dietary carbohydrate apparently modulates the serum concentrations of TBPA and RBP, independently of caloric intake, since ingestion of a eucaloric CRD by normal weight individuals also decreased the serum concentration of the two visceral proteins.

Adult↗