Comparative study of autonomic nervous system activity in malnourished and normal children in India

Abstract

Information on the relationship between autonomic functions and malnutrition in children is scant. In the present study, autonomic function tests were conducted in 30 normal subjects and 30 malnourished children aged between 5 and 10 years. The tests performed included tests for parasympathetic functions (resting heart rate, standing-to-lying ratio, lying-to-standing ratio and Valsalva ratio) and tests to assess sympathetic function (hand grip test, galvanic skin resistance). The malnourished children had significantly lower mean weights-for-age (-2.6 Z vs -1.5 Z; p = 0.001), heights-for-age (-2.5 Z vs -1.5 Z; p = 0.001) and weights-for-height (-1.6 Z vs -0.8 Z; p = 0.001). Parasympathetic function tests evaluated were significantly affected in malnourished children. Resting heart rate was significantly higher in the malnourished group (90.6 vs 82.5/min; p = 0.001). The other parasympathetic function tests had significantly lower mean values than in the control group, namely, standing-to-lying ratio (1.25 vs 1.32; p = 0.026), lying-to-standing ratio (1.23 vs 1.29; p = 0.021) and Valsalva ratio (1.26 vs 1.28; p = 0.037). Of the sympathetic function tests conducted, there were no differences between the two groups for hand grip test but galvanic skin resistance was significantly higher in the malnourished subjects (190.1 vs 149.73; p = 0.001). It is concluded that autonomic nervous system function is significantly compromised in malnourished children.

Cardiac changes in moderately malnourished children and their correlations with anthropometric and electrolyte changes

“…4,6,9 It is known that the autonomic nervous system function is significantly affected in malnourished children. 11 The process of cardiac repolarization may change depending on which section of the heart was damaged. Consequently, QT dispersion (QTd) was affected.…”

Assessment of Autonomic Function Activity in Obese Children

“…The children were categorized as normal or obese on the basis of classification used by Garrow [3]. BMI was calculated as weight (kg)/height (m) 2 . The BMI range of 20 to 24.9 was classified as normal.…”

“…Also, there is close association of obesity and obstructive sleep apnea [1]. In addition there is also evidence of autonomic dysfunction in malnourished children [2] but little information is available as regards to the autonomic status is in obese children. Obesity results from a chronic imbalance between energy intake and energy expenditure.…”

Long-Lasting Effects of Undernutrition

“…For example, a study that compared normal and undernourished children in India from 5 to 10 years of age [80], employed tests to assess the function of the parasympathetic nervous system (resting heart rate and the ratio between the measurements obtained lying down and standing, as well as during expiratory pressure for 15 seconds—known as the Valsalva ratio), and the function of the sympathetic nervous system (measurement of blood pressure during static exercise by means of the execution of a test in which the individual exerted pressure with their hand on a determined object for one minute, and a test to measure the galvanic skin response). The results showed that the resting heart rate was significantly higher in the undernourished group; likewise, the tests to examine the parasympathetic function suggested that this was compromised in these children.…”