Kunihiko Aizawa

Effects of lifestyle modification on central artery stiffness in metabolic syndrome subjects with pre-hypertension and/or pre-diabetes.

AIMS To examine the effects of a 24-week lifestyle intervention prescribed by family doctors on carotid artery stiffness in metabolic syndrome (MS) subjects with pre-hypertension and/or pre-diabetes. METHODS Sixty-three middle-aged and older subjects with pre-hypertension and/or pre-diabetes were divided into subjects without MS (MS-) and with MS (MS+). MS components and carotid artery stiffness by ultrasound were determined at baseline, at 8 weeks, and following the 24 weeks of lifestyle intervention. Family doctors prescribed an individually customized lifestyle prescription for aerobic exercise and Mediterranean-style diet. RESULTS Carotid artery distensibility significantly increased in MS+ following the 24 weeks of intervention compared with baseline (0.191+/-0.012 vs. 0.143+/-0.011, 1/mmHg x 10(-2), p<0.05). Similarly, beta stiffness index decreased in MS+ following the 24 weeks of intervention (9.8+/-1.1 vs. 12.5+/-1.1 AU, p<0.05). Following the intervention, waist circumference, BP and fasting glucose levels reduced in MS+ (all p<0.05), and 13 MS+ subjects were free from MS. CONCLUSIONS The results show the reduction of carotid artery stiffness and the improvement of some MS components in MS subjects, suggesting a favorable effect of our lifestyle modification strategy on central artery stiffness as well as MS components in MS subjects.

Acute and Chronic Impact of Dynamic Exercise on Arterial Stiffness in Older Hypertensives

Arterial stiffness increases with ageing and hypertension. Regular physical activity has been recommended as an important management component of hypertension. The purpose of this study was to examine the acute impact of maximal dynamic exercise and the effect of 20 weeks of aerobic exercise on arterial stiffness of the carotid and brachial arteries in older hypertensives. Nine previously sedentary and treated older hypertensives (2 men and 7 women, age 68.2 ± 5.4 yrs) performed maximal treadmill exercise to volitional fatigue while arterial stiffness indices (arterial distensibility and β stiffness index) were measured prior to, immediately (about 10 min) following, and 24 h following maximal exercise. These measurements were repeated following 20 weeks of moderate intensity aerobic exercise training. Maximal exercise had no impact on arterial stiffness indices immediately and 24 h following exercise intervention. Following 20 weeks of training, arterial stiffness indices remained unchanged at rest and following maximal exercise. These data show that, in older hypertensives, 1) acute maximal dynamic exercise had no impact on arterial stiffness of the carotid and brachial arteries, and 2) 20 weeks of moderate intensity aerobic exercise training failed to modify arterial stiffness.

Metabolic syndrome, endothelial function and lifestyle modification.

We evaluated (1) endothelial function (FMD, ICAM-1 and VCAM-1) cross-sectionally in subjects with (MS+) and without (MS-) metabolic syndrome who were at increased risk for cardiovascular disease due to either HNBP and/or IGR, and (2) examined in a subgroup of subjects the effects of 24-week lifestyle modification on endothelial function. MS components, FMD by Doppler ultrasound, ICAM-1 and VCAM-1 by fasting blood samples were assessed. All of the endothelial functions were similar between MS— and MS+.Although waist circumference, blood pressure, and fasting glucose showed improvements, endothelial function remained unchanged following the intervention. The results showed that in our subject population, MS does not reduce endothelial function, and our 24-week lifestyle modification programme did not result in an improvement in endothelial function in MS+ despite the improvements in some MS components.

High-normal blood pressure, impaired glucose regulation and metabolic syndrome have variable impact on central artery stiffness

AIMS This cross-sectional study compared carotid artery stiffness in metabolic syndrome (MS) subjects with high-normal blood pressure (HNBP) and/or impaired glucose regulation. METHODS Eighty-nine subjects (40M and 49F, 53.5+/-9.3 years) with either HNBP, impaired glucose regulation, or both were studied. The following measurements were included: risk factors for MS (waist circumference, blood pressure (BP), glucose, triglycerides and high-density lipoprotein (HDL) cholesterol), and carotid artery stiffness (Doppler ultrasound). RESULTS Forty-four subjects (20M and 24F) were classified as without MS (MS-) and 45 subjects (20M and 25F) as with MS (MS+). As expected, each component of MS was different between the groups (all p<0.05). Arterial distensibility in MS+ was significantly lower than in MS- (0.152+/-0.010 vs. 0.181+/-0.0091/mmHg x 10(-2), p<0.05), while beta stiffness index was not different between the two groups (12.3+/-1.1 vs. 10.5+/-1.1 AU, p=0.115). Multivariate analysis revealed that carotid artery stiffness was independently associated with resting HR together with age (both p<0.05). CONCLUSIONS These results show that, in subjects with HNBP and/or impaired glucose regulation: (1) the presence of MS decreases arterial distensibility of the carotid artery but do not increase beta stiffness index and (2) the presence of MS dose not synergistically increase carotid artery stiffness.

Longitudinal Changes in Central Artery Stiffness with Lifestyle Modification, Washout, and Drug Treatment in Individuals at Risk for Cardiovascular Disease

We assessed 17 middle-aged and older individuals (58.0 +/- 7.9 years, 7 females) at risk for cardiovascular disease regarding: (1) Whether carotid artery stiffness (cAS) would be reduced with a 1-year lifestyle modification program, (2) to what degree cAS would return following washout (mean of 26.9 +/- 4.0 months) from the active intervention, and (3) whether a 24-week telmisartan treatment would reduce cAS more than our lifestyle modification program. cAS by Doppler ultrasound, cardiovascular disease risk factors, and exercise capacity were assessed at three points: Following the 1-year lifestyle modification, following the washout period, and following a 24-week telmisartan treatment. Following telmisartan, systolic blood pressure (SBP) was significantly decreased (114.8 +/- 12.3 mmHg) compared to baseline (127.9 +/- 12.7 mmHg) and following the washout period (126.1 +/- 14.9 mmHg). Similarly, diastolic blood pressure (DBP) was significantly lower following telmisaratn than following the washout period. Exercise capacity was increased following lifestyle modification but returned to the baseline level following the washout period. Following the lifestyle modification program, cAS was significantly reduced, and this reduction was maintained following the washout period. Conversely, the subsequent telmisartan treatment did not change cAS despite a significant blood pressure reduction. These results suggest that the reduced cAS achieved with lifestyle modification may not necessarily disappear following a cessation of the active program, indicating a possible role that family physicians can play in their clinical practice, and also providing a further rationale to promote lifestyle modification as an initial therapy for this population. In contrast, no additional benefit of telmisartan beyond our lifestyle intervention was observed in this study.