IJCS | Volume 33, Nº4, July and August 2020

361 > 250 mg/dl and HDL < 35 mg/dl), severe obesity, polycystic ovary syndrome, age ≥ 45 years, moderate cardiovascular risk, and hypertension (> 140/90 mmHg or antihypertensive use in adults). 3 Thus, DM can be associated with different types of complications like autonomic dysfunctions in adult diabetic patients or their relatives with the disease. However, the prevalence of children and adolescents in pre-diabetic states or even with risk factors for type 2 DM is still unknown. 4 Additionally, one of the complications of DM is its relationship with autonomic imbalance associated and cardiovascular risk, due to its effects on the blood pressure regulatory system. 5,6 Thus, quantification of parasympathetic and sympathetic cardiac autonomic modulation is fundamental as indicator of cardiovascular function, 7 because the autonomic nervous systemplays a relevant role in the maintenance of cardiac homeostasis. Therefore, evaluation of heart rate variability (HRV) allows a sensitive and anticipated indication of the individual’s health impairment. 6 Studies show that a decrease in HRV promoted by a reduction in vagal activity has been associated with adverse events in normal individuals and patients with chronic diseases, and consequent increased risk of morbidity and mortality. 8,9 Thus, this study aims to evaluate the influence of a family history of diabetes on cardiac autonomic modulation. Materials and Methods Sample This study is part of a large Brazilian national project called Systemic Arterial Hypertension in Children and Adolescents (HASCA in Portuguese), which aims to monitor and study the development of hypertension in the early stages of life of the Brazilian population. HASCA is a national multicenter study based on nine Brazilian cities (Sao Luis, Pelotas, Sao Paulo, Aracaju, Porto Velho, PortoAlegre, BeloHorizonte, Rio de Janeiro, and Vitoria). The sample consisted of 69 adolescent volunteers aged 11 to 18 years, selected by convenience, with 46 participants without a family history of diabetes (controls) and 23 with a family history of diabetes (FHD). Participants of this study were students from a state public school (Rio Anil Integrated Center - CINTRA) in São Luís, Brazil, which was randomly chosen by a simple draw among public schools. To participate in the study, individuals should be present at all stages of data collection, which consisted of: (1) public call for the study and explanation about the project; (2) signature of the informed consent form by the parent or guardian of the child or adolescent, and signature of the informed consent form by the child or adolescent participating in the project; (3) assessment of anthropometric measurements and sexual maturation, administration of sleep quality questionnaires and physical activity level, and collection of capillary blood glucose and hemodynamic data. Subjects who were absent in any of the phases of the study, patients who reported to have any disease that may affect blood pressure (cardiovascular disease, chronic arterial hypertension, vasovagal syncope), and those using any medication to control blood pressure were excluded. The study was approved by the research ethics committee of the Universidade Federal do Maranhão approval number 1378142 in accordance with the 466/12 resolution of the BrazilianNational Health Council of the Ministry of Health. Body mass index For measurement of bodyweight, a Filizola ® scale with a capacity of 150 kg and a sensitivity of 0.1 kg, previously calibrated, was used. Volunteer werewearing light clothes and not wearing any accessories (e.g. bracelet, watches, ring). Heightwasmeasuredusing a Trena EST 23 ® compact stadiometer (2.10 m height), attached to the scale. The patient’s head was positioned in the horizontal plane; the patient was barefoot, arms hanging loosely at their sides and heels straight, touching the stadiometer. 10 From these measurements, the BodyMass Index (BMI) was calculated, obtained by the ratio of weight (kg) by height squared, 11 to assess the nutritional status of participants. Waist circumference Waist circumference (WC) was measured using an inelastic measuring tape at the edge of the iliac crest, with participant in expiration.12WCwas classified according to the criteria and cutoffs proposed by Fernández et al., 13 2004: < p10 (low) > p10 and < p75 (adequate); > p75 and < p90 (high) > p90 (very high). 13 Pittsburgh Sleep Quality Index (PSQI) The Pittsburgh Scale, a self-administered questionnaire that assesses sleepqualityover thepastmonth,was applied. Dias-Filho et al. Family history of diabetes and autonomic nervous system Int J Cardiovasc Sci. 2020; 33(4):360-367 Original Article