Increased osteoprotegerin level is associated with impaired cardiovagal modulation in type-2 diabetic patients treated with oral antidiabetic drugs.

BACKGROUND: An increased osteoprotegerin (OPG) level has been reported in both type-2 diabetes mellitus (T2DM) and cardiovascular diease (CVD) that are linked to sympathovagal imbalance (SVI). We explored the link of osteoprotegerin with cardiovagal modulation in T2DM. METHODS: We assessed fasting serum OPG, high-sensitive C-reactive protein (hsCRP), glucose, insulin and lipid profile in patients having T2DM receiving oral antidiabetic drugs (OAD) (n = 42) compared with age, gender and body composition-matched healthy participants without diabetes (n = 42). Rate pressure product (RPP), spectral indices of heart rate variability (HRV) and body composition were recorded in both the groups. Association of HOMA-IR and OPG with various parameters were assessed. RESULTS: Osteoprotegerin, HOMA-IR, hsCRP, coronary lipid risk factor were significantly increased, markers of cardiovagal modulation (TP, SDNN, RMSSD) were considerably decreased, ratio of low-frequency to high-frequency (LH-HF ratio), the indicator of SVI, and RPP, the marker of myocardial work stress were significantly higher in patients with diabetes, suggesting an overall elevated CVD risks in them. HOMA-IR was correlated with RMSSD, lipid risk factors and OPG. Rise in OPG was correlated with decreased cardiovagal modulation in patients with diabetes. There was significant contribution of OPG in decreasing TP, suggesting impaired cardiovagal modulation. CONCLUSION: T2DM patients receiving OAD had higher cardiometabolic risks compared to age, gender and body composition-matched healthy individuals. Increased level of OPG is linked to decreased cardiovagal modulation in T2DM patients.

Assessment of Cardiovascular Autonomic Functions and Baroreceptor Reactivity in Women with Premenstrual Syndrome.

OBJECTIVES: The study was conducted to assess the autonomic status of women with mild PMS using short-term heart rate variability (HRV) analysis and conventional autonomic function tests (CAFT). METHODS: Sixty females in the age group 17-25 years with mild premenstrual syndrome were identified using a self-report questionnaire, the shortened premenstrual assessment form. HRV and CAFTs were recorded 1- 5 days prior and 8-10 days after menstruation. RESULTS: The subjects showed a significant increase in HR and SBP in luteal phase. In HRV, an increase in mean HR and LF-HF ratio were seen in the luteal phase whereas an increase in the NN50, RMSSD and pNN50, HF, HF(nu) and TP were seen in the follicular phase. In CAFT, no change in HRB, 30:15 and El I ratios but increase in ?DBP(ihg) in the luteal phase was seen. CONCLUSION: The increase in HR and SBP in the luteal phase could be because increased water and salt retention due to the ovarian steroids. A decrease in HRV, increase in ?DBPihg with no change in 30:15 ratio in the luteal phase could be attributed to delayed withdrawal of ovarian hormones in the luteal phase.

Effect of short-term practice of breathing exercises on autonomic functions in normal human volunteers.

BACKGROUND & OBJECTIVES: Practice of breathing exercises like pranayama is known to improve autonomic function by changing sympathetic or parasympathetic activity. Therefore, in the present study the effect of breathing exercises on autonomic functions was performed in young volunteers in the age group of 17-19 yr. METHODS: A total of 60 male undergraduate medical students were randomly divided into two groups: slow breathing group (that practiced slow breathing exercise) and the fast breathing group (that practiced fast breathing exercise). The breathing exercises were practiced for a period of three months. Autonomic function tests were performed before and after the practice of breathing exercises. RESULTS: The increased parasympathetic activity and decreased sympathetic activity were observed in slow breathing group, whereas no significant change in autonomic functions was observed in the fast breathing group. INTERPRETATION & CONCLUSION: The findings of the present study show that regular practice of slow breathing exercise for three months improves autonomic functions, while practice of fast breathing exercise for the same duration does not affect the autonomic functions.