Impaired postexercise cardiovascular autonomic modulation in middle-aged women with type 2 diabetes.
BACKGROUND
Type 2 diabetes is associated with cardiovascular autonomic dysfunction. Postexercise autonomic modulation may be different in obese individuals with and without type 2 diabetes. We examined postexercise responses in nondiabetic and diabetic women aged 40-60 years.


METHODS
Hemodynamics, high-frequency and low-frequency of RR interval, low-frequency of systolic blood pressure variability and baroreflex sensitivity were evaluated before and after a 20 min walk at approximately 65% of VO2 peak in eight lean, 12 obese without type 2 diabetes and eight women with type 2 diabetes. Postexercise measurements were obtained at 10-15, 20-25 and 30-35 min.


RESULTS
Systolic blood pressure decreased at 10 (P<0.001) and 20 min (P<0.01) in all groups. Total peripheral resistance decreased at 10 min in all women, but the subsequent increase at 20 min was greater (P<0.01) in lean than in diabetic women. Log-transformed low-frequency of systolic blood pressure increased (P<0.01) at 10 and 20 min in all women, but the increase at 10 min was smaller (P<0.05) in diabetic than in lean women. Heart rate was increased (P<0.001) at 10 min in all women and at 20 min in both obese groups. Both log-transformed high-frequency of RR interval and baroreflex sensitivity decreased at 10 and 20 min of recovery in all groups. A group-by-time interaction (P<0.05) was observed for heart rate and baroreflex sensitivity as a lower heart rate and higher baroreflex sensitivity were observed in lean women than in women with type 2 diabetes.


CONCLUSIONS
Reduced postexercise baroreflex sensitivity and responses to autonomic cardiovascular activity contribute to an attenuated recovery of heart rate and total peripheral resistance after brisk walking in middle-aged obese women with type 2 diabetes.
Figueroa
Arturo
A
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32306-1493, USA. afiguero@fsu.edu
Baynard
Tracy
T
Fernhall
Bo
B
Carhart
Robert
R
Kanaley
Jill A
JA
D000328:Adult; D000704:Analysis of Variance; D000886:Anthropometry; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017704:Baroreflex; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D002302:Cardiac Output; D002319:Cardiovascular System / Q000503:physiopathology*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D015444:Exercise; D017079:Exercise Tolerance; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology; D010101:Oxygen Consumption; D014655:Vascular Resistance
D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin