Hypertension (HT) has been known since times immemorial to be one of the major causes of morbidity and mortality. It contributes to atherosclerotic cardiovascular disease, increasing its risk 2-3 times and is also associated with dyslipidemia, insulin resistance, glucose intolerance and obesity (1). The age of onset of hypertension is now earlier than before, making it essential that early detection of people who could be future hypertensives is done. Therefore, cardiovascular reactivity to stress in predicting future hypertension becomes important. In this fast paced age most people are exposed to mental stress which is the most common and prevalent form of stress. Increase in blood pressure (BP) in response to emotional arousal is well known, but support for this hypothesis of reactivity in predicting future hypertension is limited. We are attempting here to put forth a review of the various endeavours done so far to support this hypothesis.

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.

There is much evidence regarding autonomic dysfunction in obesity in adults, but information on autonomic status in obese children is scant. In the present study autonomic function tests were conducted in 30 normal and 30 obese children aged between 5 and 10 years. We performed tests for parasympathetic function (resting heart rate, S:L ratio (standing to lying ratio), 30:15 ratio and Valsalva ratio) and tests to assess sympathetic function (blood pressure response to hand grip test and cold pressor response). The children were classified as normal and obese on the basis of BMI (body mass index). Children with BMI between 20 to 24.9 were classified as normal and those with BMI > 30 as obese. The mean values of hand grip test and cold pressor response were significantly lower in the study group compared with controls (P < 0.05), however the Valsalva ratio was higher in the obese compared with normal children. Hence, our study showed compromised autonomic nervous system functions in the obese group compared with controls

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