Study of subclinical chronotropic response to acute exercise in children of type 2 diabetic parents
Authors: N Suchitra , Jain Manila , G Dayananda 
Published: February 2024

Background: Type 2 diabetes mellitus (T2DM) has multiple pathogenesis. Hereditary propagation marks the genetic role as a very certain factor in the causation of T2DM. Reports have suggested that individuals with a family history (FH) of T2DM exhibit an altered chronotropic response even before the manifestations of the disease. Physical exercise is a proven way to extract any of the underlying cardiovascular abnormalities. These abnormalities may not be present during rest and identifying them can be useful as a good estimate of the individual’s cardiac functional sufficiency. After the stoppage of exercise, heart rate recovery (HRR) gives a thought toward the consideration of the coordinated equilibrium of the parasympathetic and sympathetic neural pathways. The withdrawal of the sympathetic influence and simultaneous parasympathetic reactivation make HRR as a measure of the underlying autonomic dysfunction. The early outcomes of cardiac effects in healthy children of T2DM parents were studied. Any evidence of changes observed will suggest that such individuals can avert and retard the genetically propagated diseases by following an appropriate healthy lifestyle.

Aims and Objectives: (1) To assess subclinical cardiac autonomic dysfunction by way of an episode of acute aerobic exercise and study heart rate (HR), HRR, and blood pressure (BP) parameters in children of T2DM. (2). To compare above assessment parameters among the 2 groups - children of T2DM and children of non-diabetic parents.

Materials and Methods: The present study is a cross-sectional observational study comprising 120 subjects in the age group of 18–40 years, 60 Cases – children of T2DM parents and 60 age-matched Controls – children of non-diabetic parents. HR and BP were measured at rest, during exercise, immediately after (Peak HR and BP), 10 min, 20 min, and 30 min after completion of exercise. An automated multipara monitor (RMS-Phoebus P513) was used to record these parameters. An informed written consent and ethics committee approval from the institution was taken. All data were summarized and statistically analyzed. Values for statistical analysis are expressed as Mean ± standard deviation (SD) and for statistical significance, P < 0.05 was considered.

Results: Basic attributes, anthropometry of both cases and controls were comparable. Blood glucose parameters despite being in normal range, were higher in cases (P > 0.05). HR, BP parameters at rest, and their response (behavior) to exercise were similar in both groups. Cases had an increased HR and BP with an increase in exercise duration, at peak exercise and during the early phase of recovery but returned to baseline levels following a total recovery period (30 min).

Conclusion: Young euglycemic, non-diabetic children of T2DM parents have an altered chronotropic response to exercise. There is an increased HR and BP response during peak exercise, beginning and early phase of the recovery period. Such a dysregulation is probably suggestive of higher cardiovascular risk. This emphasizes a healthy lifestyle and early detection.