Abstract
Introduction. Obesity remains one of the key modifiable risk factors for cardiovascular diseases, making the search for more precise tools to assess its impact on the cardiovascular system particularly relevant. In clinical practice, obesity is traditionally assessed using the body mass index; however, this method does not distinguish between fat and muscle mass, reflect fat distribution, or account for the metabolic changes characteristic of abdominal obesity. These limitations have stimulated the development of more informative body-shape indices, among which the body shape index and the body roundness index have attracted attention. The aim of the study is to assess the informativeness of new anthropometric indices (the body shape index and the body roundness index) in comparison with the traditional body mass index for stratifying young people into groups in the study of heart rate variability.
Materials and methods. The study included 40 participants, who were divided into two groups according to low and high values of each of the three indices. Heart rate variability was analysed based on 5-minute electrocardiogram recordings at rest and during functional tests (hyperventilation and orthostatic tests). Differences were considered statistically significant at p 0.05.
Results. During functional tests, stratification according to all three anthropometric indices revealed similar autonomic patterns: in the main group, the contribution of the parasympathetic component (% HF) during hyperventilation was 5–16% lower, depending on the index used for calculation, while the contribution of the sympathetic component (% LF) during the orthostatic test was 4–21% lower compared with the control group. The body roundness index proved to be the most informative: when this index was used, individuals with a high index value demonstrated a statistically significant 30% reduction in the sympathovagal index (p = 0.048) and a 9% prolongation of the RR15 interval (p = 0.046) compared with individuals with a low index value, while the difference in RR30 reached 6%, representing the greatest difference among all three indices.
Discussion and conclusion. In the study of autonomic regulation disorders in young individuals with excess body weight, the use of the body shape index and body roundness index for stratification into groups represents a rational and promising alternative to the body mass index. The body roundness index demonstrates the greatest informativeness with regard to heart rate variability parameters, which is attributable to its integration of indicators of abdominal obesity and constitutional characteristics. The threshold values of these indices require validation in larger samples, taking into account sex and additional modifiable factors.