Short-term effects of alterations in dietary fat on metabolic control in IDDM

OBJECTIVE

Two experimental diets were evaluated to investigate the hypothesis that dietary fat has an independent influence on metabolic control in IDDM.

RESEARCH DESIGN AND METHODS

The diets had similar CHO contents (26 and 22% of energy intake) but differed markedly in fat (53 vs. 16% energy) and protein (20 vs. 62% energy). We had 10 subjects follow the low-CHO, high-fat diet, and 8 subjects follow the low-CHO, low-fat, high-protein diet. In each case, markers of glycemic and lipid control obtained after adherence to the experimental diet for 2 wk were compared with corresponding data from a preceding control period during which subjects had followed their usual diet (protein 18-19%, CHO 41-46%, fat 33-37%).

RESULTS

Despite the low CHO content of the high-fat diet, insulin requirements were unchanged relative to the control diet. Moreover, the glycemic response to a standard breakfast was elevated significantly (P < 0.001), suggesting that insulin resistance had either been induced or exacerbated. The small rise in total cholesterol concentration in response to the high-fat diet was accounted for by a rise in HDL cholesterol. Glycemic control and lipid metabolism were unchanged after the low-CHO, low-fat diet, although insulin requirements fell by an average of 6 U/day (P < 0.05) relative to those recorded during the 2-wk control period.

CONCLUSIONS

Diets high in fat are deleterious to glycemic control in IDDM, but general applicability is limited by the small sample size and short duration of this study.

Metabolic effects of dietary fructose in diabetic subjects

OBJECTIVE

To assess the metabolic effects of chronic dietary fructose consumption in diabetic subjects.

RESEARCH DESIGN AND METHODS

Six type I and 12 type II diabetic subjects consumed, in random order, two isocaloric study diets for 28 days. In one diet, 20% of energy was derived from fructose. In the other diet, < 3% of energy came from fructose, and carbohydrate energy was derived primarily from starch. Both study diets were composed of common foods. All meals were prepared in a metabolic kitchen where all foods were weighed during meal preparation.

RESULTS

Mean plasma glucose, urine glucose, and serum glycosylated albumin values were lower during the fructose diet than during the starch diet, but the differences achieved only marginal statistical significance. The day-28 value for mean plasma glucose was 12.5% lower (P = 0.03) during the fructose diet than during the starch diet. At days 14, 21, and 28, fasting serum cholesterol and LDL cholesterol were both significantly higher during the fructose diet than during the starch diet. The day-28 values for serum cholesterol and LDL cholesterol during the fructose diet were 6.9% (P = 0.008) and 10.9% (P = 0.002) higher, respectively, than the corresponding values during the starch diet. No differences were observed between the study diets in fasting serum HDL cholesterol, fasting serum triglycerides, peak postprandial serum triglycerides, or fasting serum lactate. Peak postprandial serum lactate was significantly higher during the fructose diet. Type I and type II diabetic subjects responded to the diets in a consistent way, but type I subjects experienced significantly more hypoglycemia during the fructose diet than during the starch diet.

CONCLUSIONS

A high-fructose diet may result in reduced glycemia in diabetic subjects but at the expense of increased fasting serum total and LDL cholesterol.

Glucagon-glucose (GG) test for the estimation of the insulin reserve in diabetes

The residual B-cell function was examined by means of the plasma C-peptide response 6 min after a combined injection of glucagon and glucose (GG test) or conventional glucagon test (G test) in four insulin-dependent diabetic patients (IDDM group), in 18 diabetic patients treated with insulin (Insulin group), 31 treated with oral hypoglycemic agents (SU group) and 27 treated with diet only (Diet group) and in 22 borderline cases. By GG test, 6-min C-peptide values of the IDDM group were 0.27 +/- 0.05 nM (n = 4) and were significantly lower than those of the Insulin group (0.89 +/- 0.09 nM, n = 12), the SU group (1.42 +/- 0.10 nM, n = 13), the Diet group (2.47 +/- 0.22 nM, n = 11) and the borderline cases (3.38 +/- 0.22 nM, n = 11). Patients with a 6-min C-peptide concentration below 0.75 nM by GG test appeared to be insulin-requiring patients. In the G test, plasma C-peptide concentrations at 6 min were 0.35 +/- 0.08 nM in the IDDM group (n = 2), 0.72 +/- 0.20 nM in the Insulin group (n = 7), 1.08 +/- 0.09 nM in the SU group (n = 20), 1.40 +/- 0.19 nM in the Diet group (n = 17) and 2.05 +/- 0.21 nM in the borderline cases (n = 12). Some of the Diet group patients showed extremely low C-peptide responses. When comparing the GG test and G test in individual cases, a greater C-peptide response was seen with the GG test in all cases except for IDDM patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Glycaemic index of foods

From the mid-1970s several groups realized progressively that the same amounts of carbohydrates in different foods produce quite different blood glucose curves after ingestion. The glycaemic index (GI) was introduced by Jenkins to express the rise of blood glucose after eating a food against a standard blood glucose curve after glucose (or white bread) in the same subject. The GI ranges from about 20 for fructose and whole barley to about 100 for glucose and baked potato. A table is given of representative GI values. There appears to be no general correlation between GI and per cent resistant starch in foods. Questions about methodology for GI are discussed and the factors in food that affect glycaemic response are briefly reviewed. The GI is affected by the physical form of a food, by processing and by associated fat in the food, which reduces the GI, presumably by delayed gastric emptying. As a rule the degree of insulin response to carbohydrate-containing foods is similar to the glycaemic response. Most investigators have found that the GI of a meal of mixed foods can be predicted from the (weighted) GI of its constituent foods. The GI concept is proving useful in dietary design for the management of diabetes mellitus, especially the non-insulin-dependent type. It may prove useful for prevention of diabetes and perhaps also in pre-event meals for athletes, as a factor in dental cariogenesis, in determining satiety, and conceivably regular low GI foods could delay ageing by reducing glycosylation of body proteins.

Relationship of fetal macrosomia to maternal postprandial glucose control during pregnancy

OBJECTIVE

To determine the gestational ages at which maternal hyperglycemia is most closely related to fetal macrosomia; to determine whether macrosomia is related to elevations of fasting glucose, postprandial glucose, or both; and to assess the relationship of macrosomia to maternal insulin dose and caloric intake.

RESEARCH DESIGN AND METHODS

One hundred eleven consecutive pregnant women with Class B through RF diabetes were studied longitudinally from 13 to 36 wk gestation. Macrosomia was defined by birthweight greater than 90th percentile for gestational age based on California norms. Women who delivered macrosomic infants were compared with those without macrosomic infants on pre- and postprandial blood glucose, GHb, insulin dose, macronutrient intake, and several other maternal variables.

RESULTS

Macrosomia occurred in 32 (29%) cases, although several measures indicated reasonable glycemic control throughout pregnancy. Women delivering macrosomic infants did not differ from those without macrosomic infants in maternal age, prepregnant weight, duration of diabetes, White class, macronutrient intake, GHb, or fasting glucose. Macrosomia was associated with higher postprandial glucose levels up to 32 wk gestation and lower insulin doses from 29 to 36 wk gestation. In multiple logistic regression, macrosomia was significantly associated with postprandial glucose only between 29 and 32 wk gestation. Postprandial glucose values less than 7.3 mM (less than 130 mg/dl) were associated with a higher risk of small-for-gestational-age infants (18%) compared with values above this level (1%).

CONCLUSIONS

Because macrosomia was related to postprandial glucose but not fasting glucose, we conclude that postprandial glucose measurement should be a part of routine care for diabetes in pregnancy. A target 1-h postprandial glucose value of 7.3 mM (130 mg/dl) may be the level that optimally reduces the incidence of macrosomia without increasing the incidence of small-for-gestational-age infants.

Does adequate control of diabetes in the preinfarction period improve the short-term postinfarction course?

It is uncertain whether adequate preinfarction diabetes control would alter the clinical outcome in diabetic patients once myocardial infarction has occurred. This study attempts an evaluation. Diabetic patients admitted successively to the cardiac intensive care unit with their first acute myocardial infarction were enrolled and followed throughout hospitalization. Every fourth consecutive patient with infarction, but not diabetic, was assigned to a control group. All patients were kept in the cardiac care unit for at least 48 h and vital signs and cardiac arrhythmias were continuously monitored. Radionuclide ventriculography was done within 24 h of admission and again upon discharge. When feasible, patients with postinfarction angina underwent coronary balloon angioplasty. During a 1-year period, 49 diabetic patients were studied, while 18 comparable nondiabetic patients served as controls. Diabetes was considered adequately controlled in 16 patients with glycosylated hemoglobin (HbA1c) of 8.8 +/- 0.7%, whereas in 33 patients diabetes was uncontrolled (HbA1c 14 +/- 3%), p < 0.001. No difference was found in the extent of infarct size, occurrence of heart failure, arrhythmias, and mortality when comparing the adequately with the inadequately controlled diabetics during a hospitalization period of 11 days. In diabetics, no differences were found in the short-term clinical course after acute myocardial infarction, whether the diabetes was adequately controlled or not in the preinfarction period.

Elevated plasma concentrations of beta-cell tropin (ACTH22-39) in diet-treated type II diabetic patients

beta-Cell tropin, the pituitary peptide ACTH22-39, is a potent insulin secretagogue and stimulates lipogenesis in adipose tissue in rodents. Plasma beta-cell tropin was measured fasting and after glucose infusion (5 mg.kg glucose ideal body weight-1.min0-1 for 90 min) in 10 mild diet-treated non-insulin-dependent (type II) diabetic subjects and 10 control subjects (body mass index) (BMI): 26.4 +/- 3.2 and 24.1 +/- 2.0 kg/m-2, NS, fasting plasma glucose 7.8 +/- 2.7 mM and 4.7 +/- 0.3 mM, respectively). The diabetic subjects had raised fasting plasma beta-cell tropin compared with the normal subjects (geometric mean (1 SD range): 0.49 (0.25-0.96) nM and 0.17 (0.10-0.28) nM, respectively, P = 0.007). In response to the glucose infusion, plasma glucose rose higher in the diabetic subjects (mean +/- 1 SD: 13.7 +/- 3.1 and 9.6 +/- 0.9 mM, P = 0.007) and plasma insulin was impaired in the diabetic compared with the nondiabetic subjects (geometric mean (1 SD range): 14 (8-26) and 34 (18-63), P less than 0.01). beta-Cell tropin concentrations in the diabetic subjects rose to 1.31 (0.74-2.30) nM (P = 0.007), whereas beta-cell tropin did not change in the normal subjects at 0.19 (0.11-0.91) nM. There was no overlap between glucose-stimulated plasma beta-cell tropin in the two groups (P = 0.0002). Pituitary-adrenal function, as assessed by plasma cortisol, did not differ between the two groups when fasting and did not change after the glucose infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Practice guidelines for nutrition care by dietetics practitioners for outpatients with non-insulin-dependent diabetes mellitus: consensus statement

In summary, nutrition practice guidelines for dietitians who provide outpatient care for persons with NIDDM provide a roadmap for nutrition care that allows for consistency in individualized care. A field test that compares care according to practice guidelines with usual or basic care can provide evidence, based on medical, education/behavior, and cost outcomes, that practice guidelines are not only reasonable and realistic but also effective.

Management of obesity in diabetes mellitus

A primary goal of treatment in obese individuals with NIDDM is weight loss and maintenance. Obesity is a precipitating factor for the development of NIDDM in individuals who are genetically at risk. A variety of weight-loss regimens are available to match the specific needs and lifestyles of individuals. Hypocaloric high-fiber diets have been found to be effective in achieving weight loss, as well as aiding in glycemic and lipid control. Very low calorie diets, administered under medical supervision, are useful for obese NIDDM patients with 18-55 kilograms of weight to lose. Lifestyle education appears to be an important element of any successful weight loss program.

Lipoprotein(a) concentration in diabetes: relationship to proteinuria and diabetes control

Diabetic patients are at increased risk of cardiovascular disease, particularly when proteinuria is present. Lipoprotein(a)[Lp(a)] levels were assessed in 37 patients with insulin dependent (IDDM) and in 75 patients with non-insulin dependent (NIDDM) diabetes who showed varying degrees of proteinuria and glycaemic control. Median Lp(a) in 112 diabetic patients was significantly greater than in 116 healthy controls (113 vs 48 mg/L; p less than 0.01). 86 of the patients had first morning urine albumin concentration less than 30 mg/L (normoalbuminuria = NA), 16 patients 30-200 mg/L (microalbuminuria = MA) and ten patients greater than 200 mg/L (albuminuria = ALB). There was no significant difference in median Lp(a) concentration between the three groups (NA = 108, MA = 163, ALB = 98 mg/L; p greater than 0.5). No significant difference in median Lp(a) or NIDDM treated with oral agents and/or diet (120, 98, 115 mg/L respectively; p greater than 0.7). When the 86 NA patients were divided on the basis of median fructosamine concentration (357 mumol/L), no significant difference was found in median Lp(a) levels between those grouped below or above this median (98 mg/L vs 118 mg/L; p greater than 0.5). Across all diabetics studied there was no significant correlation present between Lp(a) and urinary protein or glycaemic control. These cross-sectional results suggest that median Lp(a) concentration is increased in both IDDM and NIDDM patients, but this increase is not related to the degree of proteinuria or short-term glycaemic control.

Use of blood glucose data by families of children and adolescents with IDDM

OBJECTIVE

Prospective evaluation of the use of blood glucose test results for treatment actions by families of youth with IDDM.

RESEARCH DESIGN AND METHODS

Forty-seven patients with IDDM used reflectance meters with memory for SMBG for 28 days. Parents kept weekly diaries of six types of uses of SMBG data. We collected SMBG data from the reflectance meters, HbA1 and serum fructosamine assays, and measures of behavioral factors that could affect use of SMBG data.

RESULTS

Families recorded a mean of 4.85 data-based actions during the 28-day study, and 74% of the families reported at least one such action. Fifty percent of recorded actions consisted of management of hypoglycemia and, among the remainder, only 18% were anticipatory, proactive actions. Partial correlation analysis showed that families with more frequent use of SMBG data had less parent-child conflict about diabetes, more diabetes knowledge, and better overall treatment adherence. Use of SMBG data was unrelated to objective indices of the need for treatment adjustments or to diabetic control.

CONCLUSIONS

Most families made active use of their SMBG data, but few of these actions were proactive. Behavioral factors were stronger predictors of family use of SMBG data than were objective indices of the need for treatment adjustments. The results illustrate the need for further research on use of SMBG data and methods to enhance its impact on diabetic control.

In vivo insulin action and muscle glycogen synthase activity in type 2 (non-insulin-dependent) diabetes mellitus: effects of diet treatment

Insulin resistant glucose metabolism is a key element in the pathogenesis of Type 2 (non-insulin-dependent) diabetes mellitus. Insulin resistance may be of both primary (genetic) and secondary (metabolic) origin. Before and after diet-induced improvement of glycaemic control seven obese patients with newly-diagnosed Type 2 diabetes were studied with the euglycaemic clamp technique in combination with indirect calorimetry and forearm glucose balance. Muscle biopsies were obtained in the basal state and again after 3 h of hyperinsulinaemia (200 mU/l) for studies of insulin receptor and glycogen synthase activities. Similar studies were performed in seven matched control subjects. Insulin-stimulated glucose utilization improved from 110 +/- 11 to 183 +/- 23 mg.m-2.min-1 (p less than 0.03); control subjects: 219 +/- 23 mg.m-2.min-1 (p = NS, vs post-diet Type 2 diabetes). Non-oxidative glucose disposal increased from 74 +/- 17 to 138 +/- 19 mg.m-2.min-1 (p less than 0.03), control subjects: 159 +/- 22 mg.m-2.min-1 (p = NS, vs post-diet Type 2 diabetic patients). Forearm blood glucose uptake during hyperinsulinaemia increased from 1.58 +/- 0.54 to 3.35 +/- 0.23 mumol.l-1.min-1 (p less than 0.05), control subjects: 2.99 +/- 0.86 mumol.l-1.min-1 (p = NS, vs post-diet Type 2 diabetes). After diet therapy the increase in insulin sensitivity correlated with reductions in fasting plasma glucose levels (r = 0.97, p less than 0.001), reductions in serum fructosamine (r = 0.77, p less than 0.05), and weight loss (r = 0.78, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Lipid and lipoprotein levels in patients with IDDM diabetes control and complication. Trial experience. The DCCT Research Group

OBJECTIVES

To compare lipid and lipoprotein levels in patients with insulin-dependent diabetes mellitus (IDDM) with values in similarly aged nondiabetic subjects and analyze the effects of demographic variables, metabolic control, and other factors on the lipid and lipoprotein levels in the diabetic population.

RESEARCH DESIGN AND METHODS

Fasting total cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol levels measured during screening for the Diabetes Control and Complications Trial (DCCT) in 1569 generally healthy IDDM patients, between the ages of 13 and 40 yr and with 1-15 yr diabetes duration, were compared with values obtained with similar methods in the Lipid Research Clinics (LRC) prevalence study of nondiabetic individuals.

RESULTS

When similarly aged groups of IDDM and nondiabetic subjects were compared, higher total and LDL cholesterol and lower HDL cholesterol lipid profiles were restricted to younger (13-24 yr) female diabetic subjects. In general, IDDM males and older IDDM females had similar or slightly less atherogenic profiles than similarly aged nondiabetic subjects. Metabolic control, measured by HbA1c, and body weight (% of ideal body wt) correlated positively with total cholesterol, LDL cholesterol, and triglyceride levels.

CONCLUSIONS

Lipid and lipoprotein levels in the generally healthy IDDM volunteers for the DCCT are similar to those in the nondiabetic population. More atherogenic profiles were present only in younger IDDM women compared with nondiabetic women. The differences between the DCCT data and older studies that demonstrated more profound abnormalities in lipid levels in IDDM populations may reflect patient selection and/or changes in dietary patterns (higher-carbohydrate and lower-fat content) and in glucose control that has occurred in recent years.

[Erythropoietin level in the blood of patients with diabetes mellitus type 2]

52 patients with diabetes mellitus type II (23 of them were treated by diabetic diet, 12 were on oral antidiabetic drugs and 17 were treated by insulin), and in 31 healthy subjects the serum concentrations of erythropoietin (EPO), ferritin, iron, TIBC and hematocrit value, haemoglobin concentration and erythrocytes were measured. In diabetic patients higher but in insulin treated patients significantly higher plasma erythropoietin concentrations were found than in healthy subjects. In diabetic patients the physiological negative correlation between plasma erythropoietin concentration, haematocrit value, haemoglobin concentration and erythrocytes respectively was absent. In diabetic patients plasma ferritin concentrations were significantly higher than in normals.

CONCLUSION

patients with diabetes mellitus type II are characterized by elevated plasma erythropoietin and ferritin concentrations and dissociation of the physiological feedback between plasma erythropoietin and intensity of erythropoiesis.

The use of low glycaemic index foods improves metabolic control of diabetic patients over five weeks

The aim of the present study was to determine whether any benefit might occur from lowering the glycaemic index of diet in the medium term in diabetic patients. Eighteen well-controlled diabetic patients (12 Type 1 and 6 Type 2 non-insulin-treated), were assigned to either a high mean glycaemic index or low mean glycaemic index diet for 5 weeks each in a random order using a cross-over design. The two diets were equivalent in terms of nutrient content and total and soluble fibre content. The glycaemic indices were 64 +/- 2 (mean +/- SD) % and 38 +/- 5% for the two diets. The high glycaemic index diet was enriched in bread and potato and the low glycaemic index diet in pasta, rice, and legumes. At the end of the study periods, the following variables were improved on the low compared to the high glycaemic index diet: fructosamine (3.9 +/- 0.9 vs 3.4 +/- 0.4 mmol l-1, p less than 0.05); fasting blood glucose (10.8 +/- 2.8 vs 9.6 +/- 2.7 mmol l-1, p less than 0.02); 2-h postprandial blood glucose (11.6 +/- 2.9 vs 10.3 +/- 2.5 mmol l-1, p less than 0.02); mean daily blood glucose (12.0 +/- 2.5 vs 10.4 +/- 2.7 mmol l-1, p less than 0.02); serum triglycerides (1.5 +/- 0.9 vs 1.2 +/- 0.6 mmol l-1, p less than 0.05). No significant differences were found in body weight, HbA1C, insulin binding to erythrocytes, insulin and drug requirements, and other circulating lipids (cholesterol, HDL-cholesterol, phospholipids, Apolipoprotein A1, Apolipoprotein B). Thus the inclusion of low glycaemic index foods in the diet of diabetic patients may be an additional measure which slightly but favourably influences carbohydrate and lipid metabolism, requires only small changes in nutritional habits and has no known deleterious effects.

[Compliance with treatment in diabetic adolescents]

The study of compliance with therapy among teenagers with diabetes mellitus is a challenging task. Although several studies have addressed this problem, available knowledge in this field remains scant and the lack of understanding of factors which determine compliance with therapy hinders the development of interventions capable of helping diabetic teenagers to improve their quality of life. On the basis of a review of the relevant literature, this paper discusses compliance with therapy in the light of the specific features of teenage development. The two main theoretical models used to explain compliance with therapy in adolescent diabetics are presented. Parameters of compliance with therapy and the methods used to measure these parameters are also discussed.

Beneficial effect of a low glycaemic index diet in type 2 diabetes

Low glycaemic index foods produce low blood glucose and insulin responses in normal subjects, and improve blood glucose control in Type 1 and well-controlled Type 2 diabetic patients. We studied the effects of a low glycaemic index diet in 15 Type 2 diabetic patients with a mean fasting blood glucose of 9.5 mmol l-1 using a randomized, crossover design. Patients were given pre-weighed diets (59% energy as carbohydrate, 21% fat, and 24 g 1000-kcal-1 dietary fibre) for two 2-week periods, with a diet glycaemic index of 60 during one period and 87 during the other. On the low glycaemic index diet, the blood glucose response after a representative breakfast was 29% less than on the high glycaemic index diet (874 +/- 108 (+/- SE) vs 204 +/- 112 mmol min l-1; p less than 0.001), the percentage reduction being almost identical to the 28% difference predicted from the meal glycaemic index values. After the 2-week low glycaemic index diet, fasting serum fructosamine and cholesterol levels were significantly less than after the high glycaemic index diet (3.17 +/- 0.12 vs 3.28 +/- 0.16 mmol l-1, p less than 0.05, and 5.5 +/- 0.4 vs 5.9 +/- 0.5 mmol l-1, p less than 0.02, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)