Glycemic and insulinemic responses after ingestion of ethnic foods by NIDDM and healthy subjects

Effect of Oral Nutritional Supplements with Sucromalt and Isomaltulose versus Standard Formula on Glycaemic Index, Entero-Insular Axis Peptides and Subjective Appetite in Patients with Type 2 Diabetes: A Randomised Cross-Over Study

Oral diabetes-specific nutritional supplements (ONS-D) induce favourable postprandial responses in subjects with type 2 diabetes (DM2), but they have not been correlated yet with incretin release and subjective appetite (SA). This randomised, double-blind, cross-over study compared postprandial effects of ONS-D with isomaltulose and sucromalt versus standard formula (ET) on glycaemic index (GI), insulin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP-1) and SA in 16 individuals with DM2. After overnight fasting, subjects consumed a portion of supplements containing 25 g of carbohydrates or reference food. Blood samples were collected at baseline and at 30, 60, 90, 120, 150 and 180 min; and SA sensations were assessed by a visual analogue scale on separate days. Glycaemic index values were low for ONS-D and intermediate for ET (p < 0.001). The insulin area under the curve (AUC0-180 min) (p < 0.02) and GIP AUC (p < 0.02) were lower after ONS-D and higher GLP-1 AUC when compared with ET (p < 0.05). Subjective appetite AUC was greater after ET than ONS-D (p < 0.05). Interactions between hormones, hunger, fullness and GI were found, but not within the ratings of SA; isomaltulose and sucromalt may have influenced these factors.

Postprandial glucose and insulin levels in type 2 diabetes mellitus patients after consumption of ready-to-eat mixed meals

PURPOSE

To compare the effects of three ready-to-eat mixed meals, with a high fiber content and low glycemic index, on postprandial glycemic and insulinemic response in patients with Type 2 diabetes mellitus (T2DM).

METHODS

The current study followed a prospective, three-way, cross-over design. Twenty-four patients with T2DM consumed three ready-to-eat mixed meals, i.e., "wild greens pie" (meal 1), "chicken burgers with boiled vegetables" (meal 2) and "vegetable moussaka" (meal 3) and an oral glucose load, all providing 50 g of carbohydrates. Venous blood was collected at 0, 30, 60, 90 and 120 min postprandial. Statistical analyses included repeated measures analysis of variance and calculations of the area under the glucose and insulin curves (AUC) for each one of the test meals and the oral glucose load.

RESULTS

Patients consuming each one of the three mixed meals showed better postprandial glycemic responses compared to the oral glucose load (P < 0.001). Furthermore, patients consuming meal 3 showed a better insulinemic response compared to the oral glucose load and meal 1, after 60 and 120 min postprandial, respectively (P < 0.05). In addition, the increase observed in HOMA-IR values from T0 to T120 was significantly lower for meal 3, compared to the oral glucose load (P < 0.001).

CONCLUSIONS

The three ready-to-eat mixed meals examined in the present study were found to elicit significantly lower glycemic responses compared to the oral glucose load in diabetic patients. The mixed meals examined in the present study could be proposed as effective, palatable and practical solutions for diabetics for glucose control.

Altering source or amount of dietary carbohydrate has acute and chronic effects on postprandial glucose and triglycerides in type 2 diabetes: Canadian trial of Carbohydrates in Diabetes (CCD)

BACKGROUND AND AIMS

Nutrition recommendations for type 2 diabetes (T2DM) are partly guided by the postprandial responses elicited by diets varying in carbohydrate (CHO). We aimed to explore whether long-term changes in postprandial responses on low-glycemic-index (GI) or low-CHO diets were due to acute or chronic effects in T2DM.

METHODS AND RESULTS

Subjects with diet-alone-treated T2DM were randomly assigned to high-CHO/high-GI (H), high-CHO/low-GI (L), or low-CHO/high-monounsaturated-fat (M) diets for 12-months. At week-0 (Baseline) postprandial responses after H-meals (55% CHO, GI = 61) were measured from 0800 h to 1600 h. After 12 mo subjects were randomly assigned to H-meals or study diet meals (L, 57% CHO, GI = 50; M, 44% CHO, GI = 61). This yielded 5 groups: H diet with H-meals (HH, n = 34); L diet with H- (LH, n = 17) or L-meals (LL, n = 16); and M diet with H- (MH, n = 18) or M meals (MM, n = 19). Postprandial glucose fluctuations were lower in LL than all other groups (p < 0.001). Changes in postprandial-triglycerides differed among groups (p < 0.001). After 12 mo in HH and MM both fasting- and postprandial-triglycerides were similar to Baseline while in MH postprandial-triglycerides were significantly higher than at Baseline (p = 0.028). In LH, triglycerides were consistently (0.18-0.34 mmol/L) higher than Baseline throughout the day, while in LL the difference from Baseline varied across the day from 0.04 to 0.36 mmol/L (p < 0.001).

CONCLUSION

Low-GI and low-CHO diets have both acute and chronic effects on postprandial glucose and triglycerides in T2DM subjects. Thus, the composition of the acute test-meal and the habitual diet should be considered when interpreting the nutritional implications of different postprandial responses.

Effect of Vietnamese common diet on postprandial blood glucose level in adult females

To elucidate the effect of a typical Vietnamese diet including a high content of white rice on postprandial blood glucose levels, the present study was designed. Thirty healthy female subjects with a similar body mass index, 10 each in their twenties, forties and sixties, were recruited. Four meals with a similar protein energy percentage (13-15%) but different energy ratios of fat and carbohydrate (FC ratio) and vegetable contents were provided by cross-over design. Meal A was designed according to the commonly consumed diet in Vietnam. The FC ratio was 14:71 and 84 g of carbohydrate was from rice. Meal B contained carbohydrate in a lower ratio than meal A by fat replacement and its FC ratio was 30:57. Meal C was similar to meal A except lacking vegetables. The energy of meal A, B and C was about 2.1 MJ. Meal D was designed to match the amount of carbohydrate and fat within A and B, respectively. The FC ratio of meal D was 26:61 and the energy was about 2.4 MJ. Fasting blood glucose was measured before consumption of a test meal. Postprandial blood glucose was measured every 30 min for 2 h. Areas under the curve (AUC) were calculated to compare the glycemic response among the four test meals. There was no significant difference in AUC among the four test meals in the subjects in their twenties. In the subjects in their forties, the AUC of meal A tended to be lower than that of meal C (p = 0.07). In the subjects in their sixties, the AUC of meal A was significantly higher than that of meal B (p < 0.001). Glycemic responses showed a significant relationship with age (r = 0.26, p < 0.01); however, there was no association between glycemic responses and BMI (p = 0.20). Dietary fat ratios were inversely associated with glycemic responses (r = -0.28, p < 0.01). In conclusion, the diet with about 70% energy from carbohydrate which is commonly consumed by Vietnamese may increase glycemic response, especially in elderly people and dietary vegetables may be beneficial to prevent such an increase in glycemic response.

High-carbohydrate–low-glycaemic index dietary advice improves glucose disposition index in subjects with impaired glucose tolerance

Controversy exists about the optimal amount and source of dietary carbohydrate for managing insulin resistance. Therefore, we compared the effects on insulin sensitivity (SI), pancreatic responsivity (AIRglu) and glucose disposition index (DI=SI×AIRglu) of dietary advice aimed at reducing the amount or altering the source of dietary carbohydrate in subjects with impaired glucose tolerance (IGT). Subjects were randomized to high-carbohydrate–high-glycaemic index (GI) (high-GI, n 11), high-carbohydrate–low-GI (low-GI, n 13), or low-carbohydrate–high-monounsaturated fat (MUFA, n 11) dietary advice, with SI, AIRglu and DI measured using a frequently sampled, intravenous glucose tolerance test before and after 4 months treatment. Carbohydrate and fat intakes and diet GI, respectively, were: high-GI, 53 %, 28 %, 83; low-GI, 55 %, 25 %, 76; MUFA, 47 %, 35 %, 82. Weight changes on each diet differed significantly from each other: high-GI, -0·49 (SEM 0·29) KG; LOW-GI, -0·19 (sem 0·40) kg; MUFA +0·27 (sem 0·45) kg. Blood lipids did not change, but glycated haemoglobin increased significantly on MUFA, 0·02 (sem 0·11) %, relative to low-GI, -0·19 (sem 0·08) %, and high-GI, -0·13 (sem 0·14) %. Diastolic blood pressure fell by 8 mmHg on low-GI relative to MUFA (P=0·038). Although SI and AIRglu did not change significantly, DI, a measure of the ability of β-cells to overcome insulin resistance by increasing insulin secretion, increased on low-GI by >50 % (P=0·02). After adjusting for baseline values, the increase in DI on low-GI, 0·17 (sem 0·07), was significantly greater than those on MUFA, -0·09 (sem 0·08) and high-GI, -0·03 (sem 0·02) (P=0·019). Thus, the long-term effects of altering the source of dietary carbohydrate differ from those of altering the amount. High-carbohydrate–low-GI dietary advice improved β-cell function in subjects with IGT, and may, therefore, be useful in the management of IGT.

Determination of the differences in 2-h plasma glucose values after ingestion of carbohydrate foods and oral glucose in Caribbean non-diabetic subjects

It has been reported that mixed meals are used in clinics in developing and developed countries in screening and diagnosis of diabetes. Thus, we aimed to determine the differences in 2-h plasma glucose values after non-diabetic subjects ingested 75 g pure glucose and its equivalent content in frequently consumed carbohydrate foods in Caribbean subjects. Twenty-seven apparently healthy non-diabetic subjects (nine males, 18 females) consumed 75 g pure glucose and its carbohydrate equivalent in three ethnic test foods (bread, rice and roti) at 7 days apart. Plasma glucose and insulin levels were determined in blood samples collected before and after 60, 90, 120 and 150 min of ingestion of these foods. In comparison with each of the test foods, the postprandial 1-h and 2-h plasma glucose values and the 60, 90, 120 and 150 min incremental glucose concentrations after oral glucose load were significantly higher than the corresponding values for each of the test foods (all P<0.01). In spite of these higher postprandial glucose concentrations, the postprandial insulin responses following the oral glucose load and the test foods did not significantly differ at any time point (all P>0.05). However, the test food, roti, tended to stimulate higher absolute and incremental insulin secretions than pure glucose or any other test food (all P>0.05). Generally, the correlation between 2-h plasma glucose value after the ingestion of the pure glucose and each of the test foods was significant (all correlation coefficients were greater than 0.70, P<0.01). In conclusion, different ethnic mixed meals could serve as an alternative to glucose in routine screening and diagnosis of diabetes if its available carbohydrate content is known and quantified.

Potato and french fry consumption and risk of type 2 diabetes in women

BACKGROUND

Potatoes, a high glycemic form of carbohydrate, are hypothesized to increase insulin resistance and risk of type 2 diabetes.

OBJECTIVE

The objective was to examine prospectively the relation between potato consumption and the risk of type 2 diabetes.

DESIGN

We conducted a prospective study of 84,555 women in the Nurses' Health Study. At baseline, the women were aged 34-59 y, had no history of chronic disease, and completed a validated food-frequency questionnaire. The participants were followed for 20 y with repeated assessment of diet.

RESULTS

We documented 4496 new cases of type 2 diabetes. Potato and french fry consumption were both positively associated with risk of type 2 diabetes after adjustment for age and dietary and nondietary factors. The multivariate relative risk (RR) in a comparison between the highest and the lowest quintile of potato intake was 1.14 (95% CI: 1.02, 1.26; P for trend = 0.009). The multivariate RR in a comparison between the highest and the lowest quintile of french fry intake was 1.21 (95% CI: 1.09, 1.33; P for trend < 0.0001). The RR of type 2 diabetes was 1.18 (95% CI: 1.03, 1.35) for 1 daily serving of potatoes and 1.16 (95% CI: 1.05, 1.29) for 2 weekly servings of french fries. The RR of type 2 diabetes for substituting 1 serving potatoes/d for 1 serving whole grains/d was 1.30 (95% CI: 1.08, 1.57). The association between potato consumption and risk of type 2 diabetes was more pronounced in obese women.

CONCLUSIONS

Our findings suggest a modest positive association between the consumption of potatoes and the risk of type 2 diabetes in women. This association was more pronounced when potatoes were substituted for whole grains.

Calcium from Diet and Supplements is Associated With Reduced Risk of Colorectal Cancer in a Prospective Cohort of Women

We investigated the association between calcium intake and colorectal cancer in a prospective cohort of 45,354 women without a history of colorectal cancer who successfully completed a 62-item National Cancer Institute/Block food-frequency questionnaire. Women were followed for an average of 8.5 years, during which time 482 subjects developed colorectal cancer. We used Cox proportional hazards models, with age as the underlying time metric, to estimate risk of colorectal cancer. Cut points between quintiles of energy-adjusted dietary calcium were 412, 529, 656, and 831 mg/day. We created categories for calcium from supplements as follows: 0 mg/day (n = 25,441), 0 to 400 mg/day (n = 9,452), 401 to 800 mg/day (n = 4,176), and &gt;800 mg/day (n =6,285). Risk ratios and confidence intervals (95% CI) for increasing quintiles of dietary calcium relative to the lowest quintile were 0.79 (0.60-1.04), 0.77 (0.59-1.02), 0.78 (0.60-1.03), and 0.74 (0.56-0.98), Ptrend = 0.05. For increasing categories of calcium from supplements, the risk ratios (and 95% CI) relative to no supplement use were 1.08 (0.87-1.34), 0.96 (0.70-1.32), and 0.76 (0.56-1.02), Ptrend = 0.09. Simultaneously high consumption of calcium from diet and calcium from supplements resulted in even further risk reduction, RR = 0.54 (95% CI, 0.37-0.79) compared with low consumption of both sources of calcium. These data indicate that a difference of &lt; 400 to &gt; 800 mg of calcium per day was associated with an approximately 25% reduction in risk of colorectal cancer, and this reduction in risk occurred regardless of the source of the calcium (i.e., diet or supplements).

Glycaemic responses after ingestion of 3 local carbohydrate-based foods in West Indian patients with type-2 diabetes mellitus

BACKGROUND & AIM

Previous studies suggest that inadequate glycaemic control in diabetic patients might be related to the type of carbohydrates the patients consume regularly. Thus, we aimed to assess glucose and insulin responses after diabetic and non-diabetic subjects ingested 3 commonly consumed carbohydrate-based foods.

METHODS

Thirty-eight type-2 diabetic and 27 non-diabetic subjects were studied in 3 different occasions of 7 days apart. On each day of the study, anthropometric indices were measured and after collecting fasting blood samples, subjects randomly consumed bread, roti or rice within 10 min. Subsequently 7 ml of venous blood samples were collected at 60, 90, 120 and 150 min for determination of glucose and insulin responses.

RESULTS

Although the diabetic patients were older than the healthy subjects (P < 0.05), both subjects had similar weight, body mass index and waist and hip circumferences (P > 0.05). The mean fasting and post meal plasma glucose concentrations for the 3 test foods were higher in diabetic patients than the corresponding values for the healthy subjects (all; P < 0.001). Generally, roti elicited the highest total incremental glucose responses in the diabetic patients irrespective of ethnic group (P < 0.05).

CONCLUSION

There were variations in glucose and insulin responses to the 3 test foods. However, roti elicited the highest postprandial hyperglycaemia and should therefore be discouraged in regular dietary plan of diabetic patients.

Comparison of the effects of dried peas with those of potatoes in mixed meals on postprandial glucose and insulin concentrations in patients with type 2 diabetes

BACKGROUND

Data on the blood glucose response of diabetic patients to mixed meals containing food both rich in fiber and with a low glycemic index, such as dried peas, is scarce. Thus, the extent to which type 2 diabetic patients should take into account low-glycemic, high-fiber foods for their daily carbohydrate intake is uncertain.

OBJECTIVE

We compared the glycemic and insulinemic responses to 3 different meals based on dried peas, potatoes, or both in patients with type 2 diabetes undergoing dietary treatment.

DESIGN

The meals, prepared according to local recipes and consumed at weekly intervals in random order at lunchtime, contained comparable amounts of carbohydrate, fat, protein, and water. The carbohydrate source of the meals differed and was supplied from either dried peas (meal 1), potatoes (meal 3), or a combination thereof (meal 2). Peripheral and venous blood was sampled over 180 min.

RESULTS

The increases in postprandial plasma glucose and insulin concentrations were delayed and significantly smaller after the pea meal than after the potato meal. The areas under the glucose curve were 164 +/- 40, 257 +/- 57, and 381 +/- 40 mmol x 180 min/L for meals 1, 2, and 3, respectively (P < 0.01). The areas under the insulin curve were 13.8 +/- 4.3, 15.4 +/- 3.9, and 31.2 +/- 6.9 nmol x 180 min/L, respectively (P = 0.0514).

CONCLUSION

These findings suggest that carbohydrates in dried peas may be largely disregarded in carbohydrate counting and that type 2 diabetic patients should probably increase their consumption of low-glycemic, high-fiber foods at the expense of high-glycemic, low-fiber foods.

Long-term effect of varying the source or amount of dietary carbohydrate on postprandial plasma glucose, insulin, triacylglycerol, and free fatty acid concentrations in subjects with impaired glucose tolerance

BACKGROUND

Reducing the glycemic load (GL) is considered beneficial for managing insulin resistance. The GL can be reduced either by reducing carbohydrate intake or by reducing the glycemic index (GI).

OBJECTIVE

We studied whether these 2 dietary maneuvers have the same long-term effects on postprandial plasma glucose, insulin, triacylglycerol, and free fatty acid (FFA) concentrations in subjects with impaired glucose tolerance (IGT).

DESIGN

Thirty-four subjects with IGT were randomly assigned to high-carbohydrate, high-GI (high-GI); high-carbohydrate, low-GI (low-GI); and low-carbohydrate, high-monounsaturated fatty acid (MUFA) diets for 4 mo. Plasma glucose, insulin, and FFAs were measured from 0800 to 1600 at baseline in response to high-GI meals (60% carbohydrate, GI = 61, GL = 63) and after 4 mo in response to meals representative of the study diet.

RESULTS

Carbohydrate intake (% of energy), GI, and GL in the high-GI, low-GI, and MUFA groups (breakfast and lunch meals combined), respectively, were 60%, 61, and 63; 60%, 53, and 55; and 49%, 61, and 52. Compared with the change after 4 mo of the high-GI diet, both the low-GI and MUFA diets reduced 0-8-h mean plasma glucose concentrations by 0.35 mmol/L (P < 0.05). Mean plasma insulin was approximately 20% higher (P < 0.05) and FFAs approximately 12% lower (P < 0.05) after the low-GI diet than after the high-GI diet, with no significant effect of MUFA. Changes in 0-8-h mean plasma triacylglycerols in the 3 treatment groups differed significantly: -0.14, 0.04, and 0.18 mmol/L, respectively, with the high-GI, MUFA, and low-GI diets.

CONCLUSIONS

In subjects with IGT, reducing the GI of the diet for 4 mo reduced postprandial plasma glucose by the same amount as did reducing carbohydrate intake. The 2 dietary maneuvers had different effects on postprandial plasma insulin, triacylglycerols, and FFAs.

Dietary fiber intake and glycemic index and incidence of diabetes in African-American and white adults: the ARIC study

OBJECTIVE

To determine the association of dietary fiber and glycemic index with incident type 2 diabetes in African-Americans and whites.

RESEARCH DESIGN AND METHODS

We studied 12,251 adults aged 45-64 years and free of diabetes at baseline (1987-1989). A total of 1,447 cases of diabetes were reported between baseline and 9 years of follow-up. Diabetes status was determined by fasting glucose level > or =126 mg/dl (7.0 mmol/l), nonfasting glucose level > or =200 mg/dl (11.1 mmol/l), self-report of physician diagnosis, or use of diabetes medication. Usual dietary intake over the previous year was obtained at baseline using a 66-item food-frequency questionnaire. Nutrients were energy-adjusted using the residuals method. Proportional hazard regression analysis was used to examine dietary fiber intake and glycemic index as predictors of type 2 diabetes in both ethnic groups.

RESULTS

After adjustment for age, BMI, education, smoking status, physical activity, sex, and field center, there were no statistically significant associations of intake of total dietary fiber, fruit fiber, legume fiber, glycemic index, or glycemic load with incident diabetes. The hazard ratio for the fifth compared with the first quintile of cereal fiber was 0.75 (95% CI 0.60-0.92) in whites and 0.86 (0.65-1.15) in African-Americans.

CONCLUSIONS

This finding supports a protective role for cereal fiber in the development of diabetes in whites. More studies are needed to determine the role of dietary fiber and glycemic index in diabetes in African-Americans.

Glycemic index and insulin response to a liquid nutritional formula compared with a standard meal

OBJECTIVE

To determine the glycemic index and metabolic responses to a nutritional formula, and to compare these responses to those following an oral glucose meal and a standard test meal.

METHODS

Six male and six female healthy non-diabetic volunteers aged 18 to 48 years met screening examination and laboratory assessment criteria. Three test meals were administered, each containing 50 g of carbohydrate: nutritional formula (NF), standard test meal (ST) and a glucose test meal (GT). Each subject underwent the three test meals on separate days in randomized sequence. Blood samples were taken at intervals over 5 hours for determination of glucose, insulin and triglycerides.

RESULTS

The glycemic index was similar for the NF (60.8 +/- 13.1) and for the ST (57.8 +/- 12.9) meals. The incremental area under the curve for glucose was similar for NF and ST, but each was significantly lower than for the GT meal. The total area under the curve for insulin was significantly greater for the NF meal than for the ST meal. The serum triglyceride responses were similar for NF and ST meals.

CONCLUSION

In healthy non-diabetic subjects, the blood glucose and triglyceride responses are similar for a nutritional formula compared to an isoenergetic standard test meal. However, the insulin response differs. This information is important in managing tube-fed patients.

Enrichment of an Israeli ethnic food with fibres and their effects on the glycaemic and insulinaemic responses in subjects with non-insulin-dependent diabetes mellitus

The effects of various sources of dietary fibre on the high glycaemic index of an Israeli ethnic food, melawach, were investigated in subjects with non-insulin-dependent diabetes mellitus (NIDDM). Locust-bean (Ceratonia siliqua) gum significantly decreased the glucose response to, and glycaemic index of, melawach in these diabetic subjects (P < 0.05). It also tended to decrease their insulinaemic response and insulinaemic index, but differences were not significant. Dietary fibre from lupin (Lupinus albus) and insoluble maize-cob fibre did not affect glucose and insulin levels in NIDDM volunteers. Subjects with a BMI < 30 kg/m2 exhibited similar glucose, but not insulin, responses to fibre. Locust-bean gum had no significant effect on glycaemic response in NIDDM subjects with a BMI > 30 kg/m2, whereas insulinaemic response decreased. The results indicate that foods containing the same nutrients in almost the same amounts, but differing in added dietary fibre, lead to different physiological responses in diabetic subjects. Furthermore, insulin response should be considered when fibre is incorporated into the diabetic's diet.

Effect of local diets with added sucrose on glycemic profiles of healthy and diabetic Brazilian subjects

OBJECTIVE

We set out to determine the daily glycemic profile of healthy and non-insulin-dependent diabetes mellitus (NIDDM) persons and to test the hypothesis that small amounts of sucrose added to NIDDM meals would not change their responses.

METHODS

Thirteen NIDDM and six healthy volunteers participated in the study. They initially consumed a diet similar to their home diet and later a diabetic hospital dietary regimen, with and without 30 g/day sugar replacing equivalent food energy. The hospital diet included their usual foods: bread, milk, rice, beans, meat, vegetables and fruits at breakfast, lunch and dinner. To follow their glycemic profile we drew several blood samples during a 22-hour period.

RESULTS

The day-long plasma glucose profile of the NIDDM and healthy subjects showed similar patterns, increasing after the meals and returning later to baseline levels. The extra amount of sucrose consumed did not change the daily glycemic profile or the calculated glycemic area under the 22-hour glycemic curves. These results call attention to the importance of the 22-hour glycemic profile compared to other shorter glycemic indexes.

CONCLUSION

The 22-hour profile has obvious advantage for planning day-long diabetic diets, taking in consideration local daily foods and usual eating habits. Maintenance of a small and traditional amount of food, e.g., sucrose, without harmful effects to the subjects, is another advantage of this proposition. It improves patient compliance as well as social daily life.