Genetic variants in the SLC16A11 gene are associated with increased BMI and insulin levels in nondiabetic Chilean population

ABSTRACT Objective: To study the association of SLC16A11 gene variants with obesity and metabolic markers in nondiabetic Chilean adults. Materials and methods: This cross-sectional study included 263 non-diabetic adults. The genotype of the rs75493593 polymorphism of SLC16A11 gene was performed by real-time PCR. It's association with adiposity markers (body weight, BMI, waist circumference and fat mass percentage), metabolic markers (glucose, insulin, HOMAIR, leptin, total cholesterol, LDLc, HDLc, triglycerides, ALT, GGT and hsCRP) and blood pressure was analyzed by linear regression. Results: The minor allele (T) of the SLC16A11 gene (rs75493593) has a frequency of 29.7% among Chileans. Risk genotypes (GT and TT) were associated with a significant 1.49 mU/l increase in plasmatic insulin for each copy of the minor allele (95% CI: 0.12, 2.87, p < 0.05). This association remained significant after adjusting for socio-demographic variables, physical activity and smoking (1.36 mU/l, 95% CI: 0.16, 2.58 p < 0.05), but was lost when BMI was included as a confounding factor. Higher BMI was also significantly associated with polymorphic genotypes in SLC16A11, independent of socio-demographic variables. Conclusion: The minor allele of the SLC16A11 gene (T) is highly prevalent among Chileans and is associated with increased insulin and BMI in nondiabetic individuals. These findings suggest that the genetic variant in SLC16A11 is not only associated with type 2 diabetes as previously shown in Mexicans, but is also related to early metabolic alterations in healthy subjects that may lead to type 2 diabetes.

Genetic variants in the SLC16A11 gene are associated with increased BMI and insulin levels in nondiabetic Chilean population.

OBJECTIVE: To study the association of SLC16A11 gene variants with obesity and metabolic markers in nondiabetic Chilean adults. METHODS: This cross-sectional study included 263 non-diabetic adults. The genotype of the rs75493593 polymorphism of SLC16A11 gene was performed by real-time PCR. It's association with adiposity markers (body weight, BMI, waist circumference and fat mass percentage), metabolic markers (glucose, insulin, HOMAIR, leptin, total cholesterol, LDLc, HDLc, triglycerides, ALT, GGT and hsCRP) and blood pressure was analyzed by linear regression. RESULTS: The minor allele (T) of the SLC16A11 gene (rs75493593) has a frequency of 29.7% among Chileans. Risk genotypes (GT and TT) were associated with a significant 1.49 mU/l increase in plasmatic insulin for each copy of the minor allele (95% CI: 0.12, 2.87, p < 0.05). This association remained significant after adjusting for socio-demographic variables, physical activity and smoking (1.36 mU/l, 95% CI: 0.16, 2.58 p < 0.05), but was lost when BMI was included as a confounding factor. Higher BMI was also significantly associated with polymorphic genotypes in SLC16A11, independent of socio-demographic variables. CONCLUSION: The minor allele of the SLC16A11 gene (T) is highly prevalent among Chileans and is associated with increased insulin and BMI in nondiabetic individuals. These findings suggest that the genetic variant in SLC16A11 is not only associated with type 2 diabetes as previously shown in Mexicans, but is also related to early metabolic alterations in healthy subjects that may lead to type 2 diabetes.

Correspondence between single versus daily preference assessment outcomes and reinforcer efficacy under progressive-ratio schedules.

Research has suggested that a daily multiple-stimulus-without-replacement (MSWO) preference assessment may be more sensitive to changes in preference than other assessment formats, thereby resulting in greater correspondence with reinforcer efficacy over time (DeLeon et al., 2001). However, most prior studies have measured reinforcer efficacy using rate of responding under single-operant arrangements and dense schedules or under concurrent-operants arrangements. An alternative measure of reinforcer efficacy involves the evaluation of responding under progressive-ratio (PR) schedules. In the present study, 7 participants were given a single paired-stimulus (PS) preference assessment followed by daily MSWO preference assessments. After each daily MSWO, participants responded for each stimulus on a PR schedule. The correspondence between break points and preferences, as assessed by the 2 assessment formats, was examined. Results demonstrated that both preference assessments did equally well at predicting reinforcer efficacy, although the PS more consistently identified the most effective reinforcer.

An evaluation of resurgence during treatment with functional communication training.

Extinction-induced resurgence is the recurrence of previously reinforced behavior when another behavior is placed on extinction (Lieving, Hagopian, Long, & O'Connor, 2004). This phenomenon may account for some instances of treatment relapse when problem behavior recovers during extinction-based treatments. The current study sought to determine whether resurgence of problem behavior would reliably occur with 5 participants who received treatment with FCT. Results showed that problem behavior reemerged for all but 1 participant when the communicative response was exposed to extinction or thin schedules of reinforcement. These findings suggest that resurgence may account for some instances of response recovery during treatment, and that the described procedure may be useful for the further study of resurgence and eventual prevention of this phenomenon.

Reinforcement magnitude: an evaluation of preference and reinforcer efficacy.

Consideration of reinforcer magnitude may be important for maximizing the efficacy of treatment for problem behavior. Nonetheless, relatively little is known about children's preferences for different magnitudes of social reinforcement or the extent to which preference is related to differences in reinforcer efficacy. The purpose of the current study was to evaluate the relations among reinforcer magnitude, preference, and efficacy by drawing on the procedures and results of basic experimentation in this area. Three children who engaged in problem behavior that was maintained by social positive reinforcement (attention, access to tangible items) participated. Results indicated that preference for different magnitudes of social reinforcement may predict reinforcer efficacy and that magnitude effects may be mediated by the schedule requirement.