Association of lower habitual physical activity level with mitochondrial and endothelial dysfunction in patients with stable coronary artery disease.
BACKGROUND
Exercise training improves endothelial function in patients with coronary artery disease (CAD) through unclear mechanisms. We hypothesized that mitochondrial dysfunction related to a lower habitual physical activity level (PAL) is associated with endothelial dysfunction.


RESULTS
We assessed habitual PAL by a validated International Physical Activity Questionnaire, brachial flow-mediated dilation (FMD) and serum lactate, pyruvate, fasting glucose and lipid profiles in 105 CAD patients (age 68±10; 87% men). As defined by the lactate/pyruvate ratio (LP ratio) ≥75(th) percentile of the age-and sex-matched controls (ie, ≥18), mitochondrial dysfunction was observed in 33/105 (31%) patients. With decreasing PAL tertiles, there were significant linear trends of lower FMD (P=0.004) and higher LP ratio (P=0.009). Multivariate logistic regression found that the lowest compared with the highest PAL tertile (adjusted odds ratio=3.78, P=0.02) had more patients with high LP ratio. After adjustment for cardiovascular risk factors and medications, the lowest compared to the highest PAL tertile had significantly lower FMD (absolute decrease 1.25%, P=0.03); and high LP ratio was associated with impaired FMD (absolute reduction 1.09%, P=0.03).


CONCLUSIONS
In CAD patients, a lower level of habitual PAL is associated with impaired FMD and increased prevalence of mitochondrial dysfunction as defined by high LP ratio. Moreover, high LP ratio predicts a lower FMD, suggesting that the occurrence of mitochondrial dysfunction with lower habitual PAL is associated with endothelial dysfunction in CAD patients.
Cardiology Division, Department of Medicine, The University of Hong Kong, Hong Kong, China.
Ting-Hin
TH
Luk
Yuk-Ling
YL
Dai
Chung-Wah
CW
Siu
Kai-Hang
KH
Yiu
Sheung-Wai
SW
Li
Bonnie
B
Fong
Wai-Keung
WK
Wong
Sidney
S
Tam
Hung-Fat
HF
Tse
D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003324:Coronary Artery Disease / Q000097:blood* / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008019:Life Style; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism* / Q000473:pathology; D009043:Motor Activity; D019289:Pyruvic Acid / Q000097:blood; D012307:Risk Factors
D001786:Blood Glucose; D008055:Lipids; D019344:Lactic Acid; D019289:Pyruvic Acid