Anthropometric and laboratory surrogate markers of insulin resistance compared to the hyperglycemic clamp in adolescents: Brazilian Metabolic Syndrome (BRAMS) Study

Author(s)

Cleliani de Cassia da Silva

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2017-07-20

Examining board members

Bruno Geloneze Neto; Marcos Antonio Tambascia; Patrícia de Oliveira Prada; Marcio Correa Mancini; Tamara Beres Lederer Goldberg

• Advisor: Ana Carolina Junqueira Vasques; Bruno Geloneze Neto; Mariana Porto Zambon

Abstract

Objective: To evaluate the association of the sagittal abdominal diameter (SAD), neck circumference to height ratio (neck/height ratio) and homeostatic model assessment of adiponectin (HOMA-Adiponectin) with insulin resistance (IR) derived from the hyperglycemic clamp. Methods: Cross-sectional multicenter study with an intentional non-probabilistic sample of adolescents (10-19 years, body mass index ? 5th percentile). Three studies were carried out: 1) SAD as surrogate marker of IR (total sample: n = 520 [303 female]; clamp subsample: n = 76 [39 female]); 2) neck/height ratio as surrogate marker of IR (total sample: n = 566 [326 female]; clamp subsample: 79 [40 female]); and 3) HOMA-Adiponectin as surrogate marker of IR (total sample: n = 630 [364 female]; clamp subsample: n = 56 [29 female]). IR was assessed using the hyperglycaemic clamp. The sexual maturation (self-assessment) was determined using the Tanner pubertal stage. SAD was compared to waist circumference (WC) and HOMA-Adiponectin was compared to HOMA-IR. For statistical analysis, the stepwise multiple regression and the receiver operating characteristic curve (ROC curve) were used. Results: In the analysis including age, Tanner stages and SAD as independent variables, SAD and pubertal period were positively associated with the HOMA-IR and together explained 36.6% and 47.4% of its variance in females and males, respectively. When WC replaced the SAD in the model, it was positively associated with the HOMA-IR and, together with the pubertal period, explained 36.2% and 52.9% of its variance in females and males, respectively. In the analysis including the insulin sensitivity index (ISI) derived from the clamp as a dependent variable, in both sexes, SAD and WC were independent and negatively associated with the ISI, and explained 48.9% versus 47.9% of the its variance in females and 59.2% versus 57.9% in males, respectively. Evaluating the neck/height ratio, age and Tanner stages as independent variables, the neck/height ratio and the pubertal period were positively associated with the HOMA-IR and, together, explained 26.7% and 19.0% of its variance in females and males, respectively; in the analysis including the ISI as a dependent variable, the neck/height ratio was independent and inversely associated with the ISI, explaining 43.4% and 36.8% of its variance in females and males, respectively. In the analysis including sex, age, Tanner stages and HOMA-Adiponectin or HOMA-IR as independent variables, HOMA-Adiponectin and HOMA-IR were independent and inversely associated with the ISI, explaining 43.9% versus 63.8% of its variance, respectively. The values of area under the ROC curve (AUC) of the HOMA-adiponectin (AUC: 0.887) and of the HOMA-IR (AUC: 0.957) did not differ significantly (Z statistic: 0.918; p = 0.36). Conclusions: The SAD and the neck/height ratio were associated with IR in both sexes. When SAD was compared to WC; SAD showed equivalent associations. HOMA-Adiponectin was associated with IR derived from the clamp and presented good discriminatory power for the detection of IR. However, its accuracy was not superior to HOMA-IR (AU)

• FAPESP's process: 13/21476-3 - Validation of substitute method, laboratory and anthropometric, as indicators of insulin resistance by hyperglycemic clamp studied in adolescents. Brazilian Metabolic Syndrome Study (BRAMS)
• Grantee: Cleliani de Cassia da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate