IJCS | Volume 33, Nº4, July and August 2020

341 anddiabetesmellitus. Similarly, a recent population-based Australian surveywith 4,487women aged 20-69 years has concluded that central obesity measures (mainlyWC) are more strongly correlated with cardiovascular risk when compared with measures of general obesity like BMI. 9 In addition to WC, blood pressure, fasting glucose, HDL-cholesterol, and triglyceride levels have become important allies in clinical practice due to the increasing prevalence of metabolic disorders, such as overweight, obesity, and hypertension. All these risk factors are present in metabolic syndrome (MS), which has become a concern for many health organizations. Following the World Health Organization (WHO)’s recommendations, the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII) and the International Diabetes Federation (IDF) have emphasized the importance of fat in the etiology of MS, and WC is a crucial component of MS definition. In addition, it is interesting to note that the cut-off values for WC proposed by the IDF and NCEP-ATPIII are categorized by gender but are not age-specific, although changes in WC with age have been reported for many years. 10 To address this issue, this study aimed to investigate the relationship betweenWC and individual components of cardiometabolic diseases and to assess the ability of WC to predict cardiometabolic risk factors across age groups in adult women. Methods This observacional, cross-sectional study was approved by the Research Ethics Commitee of the Federal University of Goiás with protocol number 784.446/2014. The cohort comprised 164 women aged 20-78 years, who responded to an invitation to participate in physical exercise program for women’s health, promoted by the university and the municipal administration of the city of Santo Antônio de Goiás (Goiás, Brazil). A sample size of 164 participants was calculated considering a number of 850 women in this age range (online data published by the Instituto Brasileiro de Geografia e Estatística , IBGE 11 ), with a margin of error of 7% and confidence interval of 95%. When the sample was divided into age groups, the margin of error increased to 15%. The exclusion criteria comprisedwomen younger than 19 years, pregnant women, and women with a diagnosis of infectious or contagious disease, neurological or cognitive deficit, cardiac disease, or hypertension. Anthropometric and blood pressure measurements All WC measurements were performed by the same researcher using a flexible, inelastic tape placed directly on the skin, with the participant in a standing position andwith abdominal muscles relaxed. WCwas measured by placing the measuring tape around the abdomen at a midpoint between the top of the iliac crest and the lowest rib. Blood pressure measurements at rest were obtained with a sphygmomanometer by the same researcher with the patient in the sitting position. Two measurements were obtained from each patient, and average of both measurements was used in the analysis. Biochemical analysis Fasting blood was collected before breakfast for measurement of glucose, HDL-cholesterol, and triglycerides. Eight milliliters of blood was collected by venipuncture and aliquoted in two Vacutainer ® tubes with EDTA (Vacuplast CRAL, São Paulo/Brazil). Samples were conditioned in a refrigerated thermal box and transported in less than one hour to our laboratory to separate plasma by centrifugation. Levels of glucose were measured by the glucose oxidase (GOD) -Trinder and of HDL-cholesterol and triglycerides by glycerol phosphate oxidase (GPO) –Trinder commercial colorimetric methods using an automated analyzer (LabMax 240). International Diabetes Federation and National Cholesterol Education Program Adult Treatment Panel III cut-off values Both IDF 12 and NCEP-ATPIII 13 adopt similar cut-off values for allMS components, with the exception ofWC. In order to include bothWC cut-off values in our analysis, we divided the participants into two groups: “increasedWC,” defined by WC ≥ 80 cm (IDF) or > 88 cm (NCEP-ATPIII); and “normal WC,” defined by WC levels below those mentioned above. Other values considered to be “altered” for the purpose of this study included SBP ≥ 130 mmHg, DBP ≥ 85mmHg, fasting glucose ≥ 100mg/dL, triglycerides ≥ 150 mg/dL, and HDL-cholesterol < 50 mg/dL according to both IDF and NCEP-ATPIII criteria. Statistical analysis Continuous variables with normal distribution are presented as mean ± standard deviation (SD) and as median and interquartile range (IQR) when data followed a non-normal distribution. Initially, participants were Silva et al Waist circumference and increased blood pressure Int J Cardiovasc Sci. 2020; 33(4):340-347 Original Article