Comparison of the Effects of Three Insulinotropic Drugs on Plasma Insulin Levels After a Standard Meal

OBJECTIVE—To compare the effects of repaglinide, glipizide, and glibenclamide on insulin secretion and postprandial glucose after a single standard 500-kcal test meal. RESEARCH DESIGN AND METHODS—A total of 12 type 2 diabetic patients with early diabetes (mean HbA1c of 6.1%) and 12 matched control subjects were enrolled in this randomized, double-blind, crossover trial. Subjects received placebo, 2 mg repaglinide, 5 mg glipizide, and 5 mg glibenclamide in a random fashion during the trial. Administration of each drug was followed by a single standard 500-kcal test meal. A washout period of 7–12 days existed between the four study visits. RESULTS—All three drugs were equally effective on the total prandial insulin secretion (area under the curve [AUC] ?15 to 240 min). However, clear differences were noted in the early insulin secretion (AUC ?15 to 30 min); both repaglinide and glipizide increased secretion in nondiabetic subjects by ?61 and 34%, respectively, compared with placebo. In the diabetic patients, the difference versus placebo was 37 and 47%, respectively. The difference between glipizide and glibenclamide reached significance in both groups of subjects, whereas repaglinide was more effective than glibenclamide only in the healthy nondiabetic subject group. All three drugs were effective in decreasing total glucose AUC in the nondiabetic and diabetic population. In the nondiabetic subjects, however, repaglinide was significantly more effective than glibenclamide. The differences disappeared in the diabetic subjects, probably as a result of increased prevalence of insulin resistance in this group. CONCLUSIONS—Repaglinide and glipizide but not glibenclamide significantly enhanced the early insulin secretion in both nondiabetic and diabetic subjects with preserved ?-cell function after a single standard meal

Evaluating the Impacts of Traditional Biomass Energy Use on Agricultural Production in Sichuan, China

As crop straw and firewood are generated as by-products of food production systems, they are perceived to be sustainable energy sources that do not threaten food security by Chinese government for a long time. However, the time spent on collecting straw and firewood may create a burden on rural household, as it could reduce the available labor inputs for agricultural production, which in turn, possibly brings negative impact on food security. Building on an integrated agriculture-energy production system, a Symmetric Normalized Quadratic (SNQ) multi-output profit function (which includes labor allocations as quasi-fixed factors) is estimated to investigate the impacts of traditional biomass energy use on agricultural production in this paper. The negative signs of the calculated cross-price elasticities of supply (agricultural products and biomass energy) confirm that the relationship between biomass collection and agricultural production is competition. Moreover, the cross-price elasticities of biomass collection with respect to inputs are positive, implying that indirect link between biomass collection and agricultural production perhaps lies in household consumption decisions. The important implication of this study is that potential policy interventions for developing biomass energy in rural China could aim at enhancing food security by improving household motivation of engaging in agricultural production and slowing down the competition between biomass collection and agricultural production. It is suggested that government should attach more importance to simultaneously promote the prices of agricultural products and control the prices of intermediate inputs