Brenda Bossetti

Metabolic effects of fructose as a natural sweetener in the physiologic meals of ambulatory obese patients with type II diabetes

The long-term effects of fructose as a natural sweetener in the physiologic meals of ambulatory obese patients with type II diabetes remain uncertain. An outpatient 12-week study was therefore conducted to evaluate the metabolic effects of crystalline fructose (60 g) supplementation of the diet of nine patients with type II diabetes (Group A, mean age 57 +/- 2 years, seven women and two men). Their results were compared with age-, sex-, and weight-matched patients with type II diabetes who were similarly studied but without fructose supplementation of their usual meals (Group B). The mean +/- SEM fasting serum glucose (224 +/- 24 versus 204 +/- 14 mg/dl) and glycosylated hemoglobin (11.57 +/- 0.49 versus 10.20 +/- 0.60 percent) values progressively decreased (p less than 0.05, week 12 versus week 0) in Group A. In contrast, both parameters increased in Group B when compared with the week 0 values, but differences were not statistically significant. Levels of fasting serum triglycerides, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol remained unchanged at week 12 compared with week 0 in Group A. However, the mean apoprotein A1 concentrations increased significantly at weeks 4 and 12 in Group A, whereas only transient changes occurred in apoprotein B100 values. Levels of mean fasting serum triglycerides increased at weeks 4 (15 percent) and 12 (38 percent) in Group B; however, no significant changes occurred in the rest of the lipid, lipoprotein, and apoprotein A1 and B100 levels. Metabolic by-products of fructose such as serum lactic acid and uric acid levels remained essentially unchanged in both groups at the end of the study. In addition, no significant weight changes were observed in either group. The fructose supplementation was well tolerated without significant adverse effects. Thus, this study demonstrates that addition of moderate amounts of fructose as a natural sweetener in the physiologic mixed meal does not appear to have deleterious effects on glycemic control and lipid and lipoprotein metabolism in ambulatory obese patients with type II diabetes and poor metabolic control. Rather, a slight improvement in glycemic control and alterations in the apoprotein compositions in favor of decreased risk for coronary artery disease may occur.

The Effects of Physiologic Amounts of Simple Sugars on Lipoprotein, Glucose, and Insulin Levels in Normal Subjects

Using a crossover design, eight healthy volunteers randomly received physiologic amounts (⅓ of each subjects total carbohydrate intake) of either fructose or sucrose as the primary source of simple sugar, incorporated into isocaloric diets comprised of typical American foods. After 7 and 14 days of consuming either of the two sugars, no change occurred in fasting glucose or insulin levels. In addition, total triglyceride, totalcholesterol, low-density-lipoprotein (LDL) cholesterol, and high-density-lipoprotein (HDL) cholesterol concentrations were unaltered. Since our study used conventional foods in normal eating patterns rather than contrived formulas or excessive amounts of simple sugar, our data indicate that there is no difference between sucrose or fructose on various lipid components or glucose and fasting insulin levels in the “real world” innormal subjects.

The Impact of Socioeconomic Status on Cardiovascular Risk Factors in African-Americans at High Risk for Type II Diabetes: Implications for syndrome X

OBJECTIVE The rate of type II diabetes in African-Americans is reaching epidemic proportions. African-Americans with type II diabetes suffer from more cardiovascular diseases (CVDs) associated with diabetes than the general population. Lower socioeconomic status (SES) and family history are often cited as contributory factors to the premature development of diabetes and CVDs in the general population. However, we are not aware of any study that has examined the relationships between SES and CVD risk factors (i.e., syndrome X) in a genetically enriched African-American population at high risk for type II diabetes. RESEARCH DESIGN AND METHODS We studied 200 healthy first-degree relatives of African-American patients with type II diabetes (age 25–65 years, mean 42.5 ± 8.4 years; 42 men, 158 women). Standard oral glucose tolerance test, metabolic, and anthropometric parameters, as well as questionnaires on SES, demographic characteristics, and physical activity, were obtained for each subject. SES was divided into quartiles based on annual income. To assess the impact of insulin on CVD risk, we examined clinical characteristics and metabolic parameters according to quartiles of fasting insulin concentrations. RESULTS Clinical characteristics, including mean age, BMI, waist-to-hip ratio (WHR), percentage body fat and lean body mass, and blood pressure were not statistically different among SES quartiles. There were no significant differences in any of the metabolic, blood pressure, lipid and lipoprotein, or anthropometric parameters among SES quartiles. When examined by insulin quartile, BMI, WHR, and body fat content tended to be greatest in the fourth quartile. Similarly, fasting and postprandial serum C-peptide and glucose levels were significantly higher in the fourth quartile. We observed greater levels of very low density lipoprotein (VLDL) cholesterol and triglycerides and lower levels of HDL cholesterol in the fourth compared with the first through third insulin quartiles. Serum cholesterol and LDL cholesterol were not associated with increasing insulin concentration assessed by quartiles. We found similar systolic and diastolic blood pressure, irrespective of insulin quartiles. We found relationships between fasting insulin and systolic blood pressure (r = 0.181, P < 0.05) and triglycerides (r = 0.247, P < 0.01), VLDL cholesterol (r = 0.237, P < 0.01), WHR (r = 0.268, P < 0.005), BMI (r = 0.308, P < 0.001), and percentage of body fat (r = 0.237, P < 0.01). CONCLUSIONS The present study demonstrates no SES/income effect on CVD risk factors or syndrome × in African-Americans at high risk for type II diabetes. Clustering of several components of syndrome × was seen in individuals in the highest quartiles compared with the lowest quartiles of insulin in our high-risk African-American population. We conclude that the well-established conventional risk factors for CVD in genetically enriched African-Americans are found only in individuals with the highest insulin levels, independent of SES.

Do Sociodemographics and Economic Status Predict Risks for Type II Diabetes in African Americans

The prevalence of type II diabetes and the metabolic characteristics in high-risk African Americans were examined to determine whether certain socioeconomic and demographic characteristics (SED) increase the risk for type II diabetes in this population Study participants were high-risk African Americans between the ages of 25 and 64 years. Glucose tolerance status was assessed and questionnaires were completed to obtain information regarding SED, hypertension, and physical activity. The majority of patients had normal glucose tolerance; undiagnosed type II diabetes was identified in 36 of 164 patients. Questionnaire data revealed that, in highly selected African Americans at risk for type II diabetes, there was a higher rate of obesity, prior gestational diabetes, and undiagnosed type II diabetes despite higher educational and income levels and greater access to health care and recreational facilities. Findings indicate that African Americans may be at higher risk for type ll diabetes, regardless of socioeconomic status, due to genetic inheritance and other unknown environmental determinants. Further studies are needed to characterize SED and metabolic profiles that confer a high risk for type ll diabetes in this population

The effects of carbohydrate-enriched meals on glucose turnover and metabolic clearance rates of glucose in Type 2 diabetic patients

SummaryThe addition of fructose to natural meals elicits lower serum glucose and immunoreactive insulin responses when compared with that of sucrose and starch meals. Differences in rates of splanchnic glucose appearance and peripheral glucose disposal may be partly responsible. To evaluate the role of both parameters after different carbohydrate-enriched meals, we measured the arterialized venous blood glucose, immunoreactive insulin and gastric inhibitory polypeptide concentrations in seven Type 2 diabetic patients after ingestion of isocaloric test meals. Measurements were made in a random manner on three separate occasions. Fructose, sucrose, and bread supplementation constituted 68% of the total carbohydrate content of each meal. Rates of total glucose appearance, glucose utilization and metabolic clearance rates of glucose were determined by the D3-H-3glucose prime-continuous infusion technique. The mean fasting glucose levels were similar in the three groups. Mean peak glucose concentrations and integrated incremental areas were significantly lower (p < 0.02) after the fructose-enriched meals compared with that of either sucrose or bread. The basal arterialized venous blood glucose levels were similar in all three groups. The mean incremental integrated arterialized venous blood glucose area was significantly lower in the fructose group when compared with the sucrose (p < 0.05) and bread (p < 0.02) groups. The mean fasting gastric inhibitory polypeptide levels were similar in the three groups. However, the mean incremental integrated gastric inhibitory polypeptide areas were significantly lower in the fructose group compared with the sucrose and bread groups (p < 0.01 and p < 0.05 respectively). Basal hepatic glucose outputs were not significantly different in the three groups. After each test meal ingestion, the rate of total glucose appearance was lowest for the fructose group, intermediate for the bread group and highest for the sucrose group. However, the metabolic clearance rate did not change from the baseline despite variable arterialized venous blood glucose responses after each test meal. We conclude that the differences in glycaemic responses after carbohydrate-enriched meals cannot be ascribed solely to differences in peripheral glucose disposal in Type 2 diabetic patients. Rather, the rates of total splanchnic glucose output appear to determine the ultimate glycaemic responses after different carbohydrate-enriched meals in Type 2 diabetic patients.

Serum carotene levels in female long-distance runners.

Hypercarotenemia has been associated with anorexia nervosa and hypothalamic amenorrhea. With the emergence of a spectrum of menstrual dysfunction, including anovulation in women runners, the hypothesis of hypothalamic amenorrhea in these patients has been formulated. Other authors have proposed exercise-associated amenorrhea to be distinct from hypothalamic amenorrhea based on endocrine profiles. Using carotene as an index test of hypothalamic amenorrhea, we have studied female long-distance runners (greater than 25 miles/week) and have found no difference in the carotene levels between ovulatory (midfollicular) and anovulatory runners. These data support other evidence that exercise-associated amenorrhea is distinct from hypothalamic amenorrhea.

The Role of Gastric Inhibitory Polypeptide in the Augmented Insulin Response to Sucrose

To evaluate the role of gastric inhibitory polypeptide (GIP) in the augmented insulin response to sucrose, seven normal volunteers ingested four separate meals of 100 g sucrose (S), 50 g glucose (G), 50 g fructose (F), and 50 g glucose + 50 g fructose (G + F). Serum insulin, glucose, and GIP were measured. In each of the 3 h after sugar ingestion the integrated insulin response to (S) was greater than to (G) with the 3-h total being 104% greater. The integrated glucose response to (S) was slightly greater than to (G) in the first and second hours but the differences were not significant. Integrated GIP response to (S) was greater than to (G) in hours 2 and 3. Although significant insulin and glucose responses to (F) occurred in hour 1, G + F led to insulin and glucose responses similar to G. G + F led to greater GIP levels than G in hour 3. These studies show that GIP may play a role in the augmented insulin response to S in hours 2 and 3. This may result from delayed gastric emptying and glucose absorption. The augmentation of insulin to S in the first hour may result from fructose, extra glucose equivalent of the sucrose test solution, or from endocrine mechanisms other than those subserved by GIP.

Weight change and peptide hormone responses in patients receiving interferon

The purpose of this pilot study was to describe body weight status and peptide hormone responses in patients receiving interferon (IFN) therapy for renal cell carcinoma. Eighteen patients were on therapy for approximately two to three months. Mean weight loss of the patients was 2.2 +/- 0.9 kg (mean +/- SEM) or 4.9 +/- 0.9% of prestudy weight. Of the 18 patients, 6 were further evaluated for peptide hormone responses to meal stimulation before and after treatment (mean: 1.5 months). These subjects had a mean weight loss of 4.3 +/- 1.6 kg or 7.0 +/- 3.5% of prestudy weight. Blood was drawn from subjects before and six times after they had consumed a defined formula liquid meal to provoke enteroinsular peptide release. It was discovered that one-half of this group (n = 3; Group A) had some glucose intolerance following IFN therapy, despite increased response of insulin, gastric inhibitory polypeptide (GIP), and pancreatic polypeptide (PP) to meal stimulation. Further, patients in Group A had a weight loss of -11.7 +/- 2.7% of prestudy weight, whereas the other three patients (Group B) experienced a mean loss of -2.3 +/- 1.2% (p less than 0.04). The three subjects characterized by the smaller loss of prestudy weight (Group B) had decreased glucose response to meal stimulation, despite decreased responses of insulin and GIP. Response of PP was slightly increased with treatment in group B, but the increase was not as large as that in Group A. These data may suggest that extreme weight loss and altered peptide hormone response occur in a subset of cancer patients receiving interferon therapy.