Blood Pressure Variability is Better Associated with Acute Relative Hyperglycemia Than the Heart Rate Variability in Healthy Young Adults.

BACKGROUND: Deranged cardiovascular autonomic functions are well-reported complications of diabetes mellitus, where chronic hyperglycemia is an important factor. The role of acute relative hyperglycemia on cardiovascular autonomic functions, particularly on blood pressure variability in healthy subjects, has been rarely explored. Therefore, this study aimed to examine the effect of acute relative hyperglycemia on cardiovascular autonomic functions in healthy young adults. METHODS: Beat-to-beat blood pressure and electrocardiogram were recorded to assess the heart rate variability and blood pressure variability in 42 young, healthy subjects during fasting and relative hyperglycemic states. Recorded cardiovascular parameters were analyzed in time and frequency domains. Correlations among analyzed parameters of cardiovascular autonomic variabilities were explored during fasting and relative hyperglycemic state. RESULTS: A few of the systolic, mean, and diastolic blood-pressure-variability parameters were significantly altered during acute relative hyperglycemia when compared to the fasting state. However, no significant changes were observed in any of the heart-rate-variability parameters. Also, novel significant correlations were found among many of the parameters of cardiovascular autonomic variabilities during fasting and relative hyperglycemic states. CONCLUSIONS: The blood pressure variability is affected significantly during acute relative hyperglycemia in healthy young adults; however, the heart rate variability does not show such changes. Also, many blood pressure variability parameters show significant correlations with heart rate variability and baroreflex sensitivity. It may be hypothesized that although the variabilities in heart rate and blood pressure assess cardiovascular autonomic functions, blood pressure variability is a better indicator of cardiovascular autonomic effects of acute relative hyperglycemia.

Effect of acute hyperglycemia on baroreflex sensitivity in healthy young adults.

BACKGROUND: Autonomic dysfunction, impaired baroreflex sensitivity (BRS), and deranged circulatory homeostasis have been observed in chronic hyperglycemia and found to be associated with increased cardiovascular morbidity and mortality. However, the acute effects of hyperglycemia in healthy subjects have been rarely studied. The present study explores the effect of acute hyperglycemia on conventional and unconventional parameters of BRS in healthy young adults. METHODS: For the estimation of BRS beat-to-beat blood pressure (BP) and electrocardiogram were recorded in forty-two young, healthy subjects during fasting and at 1hr of the oral glucose load. Analysis of BRS was carried out by sequence and spectral method. Number of UP-, DOWN- and ALL-sequences between ramps of BP and RR-interval were calculated as an unconventional measure of BRS along with the other conventional parameters. RESULTS: We observed significant alteration of unconventional parameters of autonomic functions [the number of sequences of UP- (p = 0.0039) and ALL-sequences (p = 0.0233) of systolic BP and RR interval; and, UP- (p = 0.0380), DOWN- (p = 0.0417) and ALL-sequences (p = 0.0313) of mean BP and RR- interval] during acute hyperglycemia as compared to the fasting state. However, no significant changes were observed in any of the conventional parameters of BRS during acute hyperglycemia as compared to the fasting state. CONCLUSIONS: Present study concludes that the unconventional parameters of BRS - the number of sequences between the ramp of BP and RR-interval - change significantly during acute hyperglycemia. However, the conventional parameters do not show significant changes during acute hyperglycemia. We may hypothesize that the relatively constant BRS is maintained at the expense of increased oscillations in the ramp of BP and RR-interval.

Bacterial Colonization of Home Nebulizers Used by Children With Recurrent Wheeze.

OBJECTIVE: To look for bacterial colonization of parts of home nebulizers used for children with recurrent wheeze and asthma. METHODS: Children aged 1 mo-12 y, using home nebulizers for recurrent cough and wheeze were enrolled from May to October, 2019. Caregivers were administered a structured questionnaire by a single researcher, during their hospital visit, to elicit information on their nebulizer cleaning practices. Samples were taken from nebulizer medicine chamber and tubing for bacterial culture and sensitivity. RESULT: Bacterial growth was observed in 17 culture samples obtained from medicine chamber and/or tubing of nebulizers used by 12 (20.3%) out of the 59 enrolled children. The bacteria isolated were Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus (Methicillin resistant S. aureus and Coagulase negative staphylococci) and these were resistant to many of the commonly used antimicrobials. Almost 20% parents had never cleaned the nebulizers. Diluent re-use was significantly associated with bacterial colonization of nebulizer parts [AOR (95% CI) 20.6 (2.26-188.5); P=0.007]. CONCLUSION: Home nebulizers, if not cleaned properly as per set protocols, may get colonized with potentially harmful bacteria. There is a need to increase awareness about their proper use amongst parents of children with recurrent wheeze.