Body Fat Distribution After Menopause and Cardiovascular Disease Risk Factors: Korean National Health and Nutrition Examination Survey 2010

Adipocyte Metabolism and Health after the Menopause: The Role of Exercise

Postmenopausal women represent an important target population in need of preventative cardiometabolic approaches. The loss of estrogen following the menopause eliminates protections against metabolic dysfunction, largely due to its role in the health and function of adipose tissue. In addition, some studies associate the menopause with reduced physical activity, which could potentially exacerbate the deleterious cardiometabolic risk profile accompanying the menopause. Meanwhile, exercise has adipocyte-specific effects that may alleviate the adverse impact of estrogen loss through the menopausal transition period and beyond. Exercise thus remains the best therapeutic agent available to mitigate menopause-associated metabolic dysfunction and represents a vital behavioral strategy to prevent and alleviate health decline in this population.

Body fat distribution and insulin resistance among Korean middle-aged women: a Korean National Health and Nutrition Examination Survey

Objective

To evaluate menopause-related changes in body fat distribution and their relationship with insulin resistance in middle-aged Korean women.

Methods

We analyzed women aged 40–60 years using data from the National Health and Nutrition Examination Survey conducted from 2008 to 2011. Body fat was measured using dual-energy X-ray absorptiometry. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR).

Results

Among 3,468 participants, menopausal women (n=1,489) had a higher body mass index (BMI) and higher trunk, arm, and head fat percentages than premenopausal women (n=1,979). However, no significant difference was found in the leg fat percentage according to menopausal status. Multivariable regression analysis for HOMA-IR showed that trunk fat percentage, BMI, and waist circumference positively correlated with insulin resistance and leg fat percentage negatively correlated after adjusting for several confounding factors, whereas menopausal status was not associated with HOMA-IR.

Conclusion

Middle-aged women not only have different body weights and BMI but also have different body fat distributions according to menopausal status. Each fat percentage change in the trunk and leg is differently associated with metabolic health, particularly insulin resistance. To evaluate the metabolic health of middle-aged women, BMI is generally noted; however, body fat distribution, which can be easily assessed using dual-energy X-ray absorptiometry, should also be considered.

Fat mass changes during menopause: a metaanalysis

OBJECTIVE

Data: Fat mass has been shown to increase in aging women; however, the extent to which menopausal status mediates these changes remains unclear. The purpose of this review was to determine (1) how fat mass differs in quantity and distribution between premenopausal and postmenopausal women, (2) whether and how age and/or menopausal status moderates any observed differences, and (3) which type of fat mass measure is best suited to the detection of differences in fat mass between groups.

STUDY

This review with metaanalyses is reported according to Metaanalysis of Observational Studies in Epidemiology guidelines.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies (published up to May 2018) were identified via PubMed to provide fat mass measures in premenopausal and postmenopausal women. We included 201 cross-sectional studies in the metaanalysis, which provided a combined sample size of 1,049,919 individuals and consisted of 478,734 premenopausal women and 571,185 postmenopausal women. Eleven longitudinal studies were included in the metaanalyses, which provided a combined sample size of 2472 women who were premenopausal at baseline and postmenopausal at follow up.

RESULTS

The main findings of this review were that fat mass significantly increased between premenopausal and postmenopausal women across most measures, which included body mass index (1.14 kg/m²; 95% confidence interval, 0.95-1.32 kg/m²), bodyweight (1 kg; 95% confidence interval, 0.44-1.57 kg), body fat percentage (2.88%; 95% confidence interval, 2.13-3.63%), waist circumference (4.63 cm; 95% confidence interval, 3.90-5.35 cm), hip circumference (2.01 cm; 95% confidence interval, 1.36-2.65 cm), waist-hip ratio (0.04; 95% confidence interval, 0.03-0.05), visceral fat (26.90 cm²; 95% confidence interval, 13.12-40.68), and trunk fat percentage (5.49%; 95% confidence interval, 3.91-7.06 cm²). The exception was total leg fat percentage, which significantly decreased (-3.19%; 95% confidence interval, -5.98 to -0.41%). No interactive effects were observed between menopausal status and age across all fat mass measures.

CONCLUSION

The change in fat mass quantity between premenopausal and postmenopausal women was attributable predominantly to increasing age; menopause had no significant additional influence. However, the decrease in total leg fat percentage and increase in measures of central fat are indicative of a possible change in fat mass distribution after menopause. These changes are likely to, at least in part, be due to hormonal shifts that occur during midlife when women have a higher androgen (ie, testosterone) to estradiol ratio after menopause, which has been linked to enhanced central adiposity deposition. Evidently, these findings suggest attention should be paid to the accumulation of central fat after menopause, whereas increases in total fat mass should be monitored consistently across the lifespan.

Association between waist-to-height ratio and anxiety in middle-aged women: a secondary analysis of a cross-sectional multicenter Latin American study

OBJECTIVE

The aim of the study was to evaluate the association between waist-to-height ratio (WHtR) and anxiety in middle-aged women.

METHODS

We carried out a secondary analysis of data from a multicenter study of women between 40 and 59 years old from 11 Latin America countries. Anxiety was assessed using the Goldberg Anxiety and Depression Scale. WHtR was calculated according to World Health Organization standards and categorized in tertiles: upper, middle, and lower using 0.45 and 0.6 as cutoff values. Prevalence ratios (PRs) and 95% CIs were calculated by generalized linear models of Poisson family with robust standard errors, both crude and adjusted models based on statistical and epidemiological criteria.

RESULTS

Data of a total of 5,580 women were analyzed. Mean age was 49.7 ± 5.5 years, and 57.9% were postmenopausal. The 61.3% of women had anxiety and mean WHtR was 0.54 ± 0.1. In the crude model, compared with women in lower tertile, those in the middle (PR: 1.07; 95% CI, 1.01-1.13) and upper (PR: 1.23 95% CI, 1.07-1.29) WHtR tertile were significantly more likely to have anxiety. In the adjusted models, only women in upper tertile were, however, more likely of displaying anxiety than those in lower tertile (PR: 1.13; 95% CI, 1.08-1.18).

CONCLUSIONS

In this series, WHtR was associated with anxiety in middle-aged women. It is advisable to further study this anthropometric measure in order for it to be incorporated in the routine clinical practice and evaluation of middle-aged women.

Viscus fat area contributes to the Framingham 10-year general cardiovascular disease risk in patients with type 2 diabetes mellitus

OBJECTIVE

To explore the correlation of the viscus fat area (VFA) with the Framingham 10-year general cardiovascular disease risk in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 202 patients with T2DM were divided into two groups based on VFA (a VFA ≥ 100 cm² group and a VFA < 100 cm² group), or four groups based on sex and age (a middle-aged male group, an elderly male group, a middle-aged female group, and an elderly female group). The correlation between the Framingham 10-year general cardiovascular disease risk and body fat indexes was analyzed.

RESULTS

Patients in the VFA ≥ 100 cm² group had higher body fat indexes and Framingham Risk Scores (FRSs) and lower levels of high density lipoprotein-cholesterol (HDL-C) when compared to the VFA < 100 cm² group (P < 0.05). Female patients had higher body fat mass (BFM) and body fat percentage (BFP) levels and a lower VFA when compared to male patients. The VFA was significantly higher in the elderly than in the middle-aged patients. The waist hip fat ratio (WHFR) was significantly higher in elderly females than in elderly males (P < 0.05). Elderly females had the highest FRS of all patients. Multiple stepwise regression analysis revealed the VFA as a contributor to the Framingham 10-year general cardiovascular disease risk after statistical correction for other multiple factors affecting cardiovascular disease risk.

CONCLUSION

The VFA is an independent factor that contributes to the Framingham 10-year general cardiovascular disease risk in patients with T2DM.

Relationship between vasomotor symptoms and metabolic syndrome in postmenopausal women

Objective This study was performed to compare the vasomotor symptoms and bone mineral density of postmenopausal women with and without metabolic syndrome. Methods We performed a cross-sectional study of 200 postmenopausal women attending routine health check-ups at Marmara Faculty of Medicine Pendik Training and Research Hospital from June 2015 to December 2015. The vasomotor symptoms scored were hot flashes and night sweats. Metabolic syndrome was defined using the consensus criteria of the International Diabetes Federation and the American Heart Association/National Heart, Lung, and Blood Institute. Results Women with vasomotor symptoms had no metabolic syndrome and were younger than those without vasomotor symptoms. There was no significant difference in vasomotor symptoms between patients with osteopenia in the femoral neck, total femur, and spine and patients with normal bone mineral density. The vasomotor symptoms were similar between smokers and nonsmokers. Conclusion The presence of metabolic symptoms is inversely associated with metabolic syndrome in postmenopausal women. Lipid abnormalities and a high body mass index may be important metabolic components associated with these symptoms. No relationship is present between vasomotor symptoms and the bone mineral density of the spine, femoral neck, and total femur.

Effect of vitamin D on the variability of blood pressure in premenopausal and menopausal hypertensive women in the area of Blida (Algeria)

OBJECTIVE

To evaluate the effect of 25 (OH) vitamin D supplementation on blood pressure (BP) variability in hypertensive women in the pre-menopausal and post-menopausal periods.

MATERIALS AND METHODS

881 hypertensive women prospectively followed for an interventional study between January 2016 and September 2017, in specialized consultation at the department of internal medicine at the Blida University Hospital (Algeria). Four hundred and thiry nine premenopausal women (group I) and 442 menopausal women (group II). The initial serum 25 (OH) D level for each group was determined by the enzyme immunoassay. In groups I and II, we identified 2 subgroups, A: insufficiency (vit D between 29 and 20ng/ml) and B: deficiency (vit D less than 20ng/L). Antihypertensive therapy was supplemented with an additional 200000IU/month cholecalciferol for the two B subgroups. The variability in BP was calculated as the ratio of mean systolic and diastolic BP during daytime and nighttime, with performing ambulatory BP measurement at baseline, 3, 6, and 12 months of follow-up.

RESULTS

At inclusion, the level of 25 (OH) D was lower (P<0.05) in subgroups IB (19.3±8.5ng/ml) and IIB (18.2±9, 5ng/ml) compared to subgroups IA (28.1±10.7ng/ml) and IIA (25.2±10.1ng/ml). After supplementation, the level of 25 (OH) D increased in subgroup IB (38.3±11.9ng/ml) and in subgroup IIB (37.3±10, 5ng/ml) and became higher (P<0.001) than in subgroups IA and IIA. Between subgroups IA and IB, at inclusion, there is no difference (P>0.05) in the SBP and DBP variability during the day and at night. After treatment, the variability of the SBP at night became lower (P<0.02) in group IB compared to group IA. In subgroup IIB, daytime variability indices were higher (P=0.04) at inclusion than in group IIA. After treatment, the variability of SBP during the day decreased but remained the highest (P<0.05) in subgroup IIB (14.8±10.8mmHg) compared to subgroup IB (12.0±8.1mmHg), as well as to subgroups IIA (10.9±9.8mmHg) and IA (10±8.1mmHg). We found a significant correlation of cholecalciferol with the variability of SBP during the day.

CONCLUSIONS

Vitamin D deficiency appears to be a factor of BP variability. Although the variability of the postmenopausal group remains higher than that of the other groups, the correction of the level of 25 (OH) D by the supply of cholecalciferol 200000 IU per month leads to a reduction in the variability of BP in the studied hypertensive women could help to prevent morbimortal complications.

Prevalence and clinical profile of metabolic syndrome in longevity: study from Guangxi Zhuang Autonomous Region, China

BACKGROUND

Metabolic syndrome (MetS) was a risk factor for cardiovascular diseases, yet the prevalence of MetS among nonagenarians and centenarians was rarely reported. Here we investigated the prevalence of MetS and its components among nonagenarians and centenarians in our Zhuang population from Bama, Guangxi Zhuang Autonomous Region, China.

METHOD

In Bama area, there registered 881 individuals who lived more than 90 years old in 269,800 local residents and our study involved 307 long-lived participants and 486 local younger (35-68 years) persons, as controls. MetS was defined according to the revised National Cholesterol Education Program's Adult Treatment Panel III (NCEP ATPIII) criteria.

RESULTS

The overall prevalence estimates of MetS among longevity group were 28.0% based on NCEP ATPIII criteria. The most common metabolic component was elevated blood pressure (61.1%), followed by raised fasting glucose (39.1%) and low high-density lipoprotein cholesterol (low HDL-C) (28.0%). The prevalence of MetS and abdominal obesity in women (33.6% and 22.1% respectively) was higher than that of men (19.8% and 3.7% respectively) (P_range < .001-0.019). Compared with controls, long-lived individuals were more likely to have two or more metabolic abnormalities (P_range < 0.001), and less likely to have zero or one metabolic abnormality (P_range < 0.001-0.020).

CONCLUSION

This study showed substantiality the prevalence and clinical profile of MetS in longevity population in Guangxi Zhuang Autonomous Region, China.

Optimal body fat percentage cut-off values for identifying cardiovascular risk factors in Mongolian and Han adults: a population-based cross-sectional study in Inner Mongolia, China

OBJECTIVE

The present study was designed to determine the optimal cut-off values of body fat percentage (BF%) for the detection of cardiovascular disease (CVD) risk factors in Mongolian and Han adults.

METHOD

This cross-sectional study involving 3221 Chinese adults (2308 Han and 913 Mongolian) aged 20-80 years was conducted in Inner Mongolia Autonomous Region, China, in 2014. Data from a standardised questionnaire, physical examination and blood sample were obtained. The BF% was estimated using bioelectrical impedance analysis. Optimal BF% cut-offs were analysed by receiver operating characteristic curves to predict the risk of diabetes, hypertension and dyslipidaemia. Binary logistic regression analysis was performed to evaluate the OR of each CVD risk factor according to obesity defined by BF%.

RESULTS

Mean BF% levels were lower in men than in women (22.54±5.77 vs 32.95±6.18 in Han, 23.86±5.72 vs 33.98±6.40 in Mongolian population, respectively; p<0.001). In Han population, the area under curve (AUC) values for BF% ranged from 0.589 to 0.699 for men and from 0.711 to 0.763 for women. Compared with men, AUCs for diabetes and clustering of ≥2 risk factors in women were significantly higher (p<0.05). The AUCs for BF% in women (0.685-0.783) were similar with those in men (0.686-0.736) for CVD risk factors in Mongolian population. In Han adults, the optimal BF% cut-off values to detect CVD risk factors varied from 18.7% to 24.2% in men and 32.7% to 35.4% in women. In Mongolian population, the optimal cut-off values of BF% for men and women ranged from 21.0% to 24.6% and from 35.7% to 40.0%, respectively. Subjects with high BF% (≥24% in men, ≥34% in women) had higher risk of CVD risk factors in Han (age-adjusted ORs from 1.479 to 3.680, 2.660 to 4.016, respectively). In Mongolia, adults with high BF% (≥25% in men, ≥35% in women) had higher risk of CVD risk factors (age-adjusted ORs from 2.587 to 3.772, 2.061 to 4.882, respectively).

CONCLUSIONS

The optimal BF% cut-offs for obesity for the prediction of CVD risk factors in Chinese men and women were approximately 24% and 34% for Han adults and 25% and 35% for Mongolian population of Inner Mongolia, China, respectively.

Lipoprotein(a) in postmenopausal women: assessment of cardiovascular risk and therapeutic options

INTRODUCTION

Lipoprotein(a) [Lp(a)], a low-density lipoprotein (LDL)-like particle, has been independently associated with increased cardiovascular disease (CVD) risk in various populations, such as postmenopausal women. The purpose of this narrative review is to present current data on the role of Lp(a) in augmenting CVD risk in postmenopausal women and focus on the available therapeutic strategies.

METHODS

PubMed was searched for English language publications until November 2015 under the following terms: "therapy" OR "treatment" AND ["lipoprotein (a)" OR "Lp(a)"] AND ("postmenopausal women" OR "menopausal women" OR "menopause").

RESULTS

Only hormone replacement therapy (mainly oral estrogens) and tibolone have been specifically studied in postmenopausal women and can reduce Lp(a) concentrations by up to 44%, although evidence indicating a concomitant reduction in CVD risk associated with Lp(a) is lacking. As alternative treatments for women who cannot, or will not, take hormonal therapies, niacin and the upcoming proprotein convertase subtilisin / kexin type 9 (PCSK-9) inhibitors are effective in reducing Lp(a) concentrations by up to 30%. Statins have minimal or no effect on Lp(a). However, data for these and other promising Lp(a)-lowering therapies including mipomersen, lomitapide, cholesterol-ester-transfer protein inhibitors and eprotirome are derived from studies in the general, mainly high CVD risk, population, and include only subpopulations of postmenopausal women.

CONCLUSIONS

Past, present and emerging therapies can reduce Lp(a) concentrations to a varying extent. Overall, it remains to be proven whether the aforementioned reductions in Lp(a) by these therapeutic options are translated into CVD risk reduction in postmenopausal women.

Association Between Drinking and Obesity in Pre- and Postmenopausal Women: Korea National Health and Nutrition Examination Survey 2010-2012

BACKGROUND

Women are more vulnerable to the adverse effects of alcohol than men. The present study aimed to investigate the link between drinking and obesity in pre- and postmenopausal women in Korea.

METHODS

We performed a cross-sectional study of 4374 premenopausal and 2927 postmenopausal women using a multistage probability cluster survey sample to produce nationally representative estimates. We assessed the subjects' alcohol drinking tendencies rates according to their drinking levels as well as Alcohol Use Disorders Identification Test (AUDIT); obesity was identified based on body mass index (BMI) ≥25 kg/m², waist circumference (WC) ≥80 cm, and waist-to-height ratio (WHtR) ≥50%. We performed t-tests and chi-square tests to assess the association between drinking and obesity.

RESULTS

In premenopausal subjects, obesity indices increased significantly as alcohol consumption rose. Significant correlations between drinking level and obesity factors were found in premenopausal women after adjusting for age (odds ratios [ORs] for BMI, WC, and WHtR were 1.58 [1.08-2.31], 1.94 [1.11-3.00], and 1.80 [1.24-2.61], respectively). Furthermore, an AUDIT score of 20 or higher indicated a significantly higher likelihood of obesity (ORs for BMI, WC, and WHtR were 2.02 [1.18-3.46], 2.75 [1.70-4.87], and 2.86 [1.78-4.59], respectively). There was a significant correlation between AUDIT scores and obesity factors after adjusting for age, energy intake, fat intake, exercise, smoking, education, and income in premenopausal women (ORs for BMI and WHtR were 1.71 [0.85-3.47] and 1.73 [0.97-3.06], respectively).

CONCLUSION

Our results suggest that alcohol is associated with a risk factor for obesity in premenopausal women.

Vasomotor symptoms and metabolic syndrome in Korean postmenopausal women

OBJECTIVE

This study aims to evaluate the association between vasomotor symptoms and risk of metabolic syndrome in Korean postmenopausal women.

METHODS

We carried out a cross-sectional study of 1,906 Korean postmenopausal women (aged 45-65 y) who were attending a routine health checkup at an institution in Korea from January 2010 to December 2012. To assess vasomotor symptoms, we created a dichotomous variable (none or present) using Menopause Rating Scale results. Metabolic syndrome was defined by the updated criteria of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III).

RESULTS

In total, 1,906 women were included in the analysis; 1,105 (58.0%) women reported some degree of vasomotor symptoms. Women with vasomotor symptoms were younger and had shorter duration of menopause, higher body mass index, larger waist circumference, more adverse lipid profile, and higher prevalence of metabolic syndrome compared with women without vasomotor symptoms. On multivariate analysis, vasomotor symptoms were associated with metabolic syndrome after adjusting for confounding factors, including age, body mass index, homeostasis model assessment of insulin resistance, duration of menopause, alcohol consumption, current smoking, and physical exercise level (odds ratio, 1.8; 95% CI, 1.3-2.4; P < 0.001).

CONCLUSIONS

The presence of vasomotor symptoms is associated with metabolic syndrome in Korean postmenopausal women. Lipid abnormalities and obesity seem to be important metabolic components associated with these symptoms. Vasomotor symptoms, if validated in longitudinal studies, may possibly serve as warning signs for identifying women at high risk for metabolic syndrome and cardiovascular disease.

Optical Coherence Tomography for Brain Imaging and Developmental Biology

Optical coherence tomography (OCT) is a promising research tool for brain imaging and developmental biology. Serving as a three-dimensional optical biopsy technique, OCT provides volumetric reconstruction of brain tissues and embryonic structures with micrometer resolution and video rate imaging speed. Functional OCT enables label-free monitoring of hemodynamic and metabolic changes in the brain in vitro and in vivo in animal models. Due to its non-invasiveness nature, OCT enables longitudinal imaging of developing specimens in vivo without potential damage from surgical operation, tissue fixation and processing, and staining with exogenous contrast agents. In this paper, various OCT applications in brain imaging and developmental biology are reviewed, with a particular focus on imaging heart development. In addition, we report findings on the effects of a circadian gene (Clock) and high-fat-diet on heart development in Drosophila melanogaster. These findings contribute to our understanding of the fundamental mechanisms connecting circadian genes and obesity to heart development and cardiac diseases.

Gender differences in metabolic syndrome components among the Korean 66-year-old population with metabolic syndrome

Background

Gender is thought to be an important factor in metabolic syndrome and its outcomes. Despite a number of studies that have demonstrated differences in metabolism and its components that are dependent on gender, limited information about gender differences on the characteristics of metabolic syndrome and its components is available regarding the Korean old adult population. This study aimed to identify gender differences in characteristics of the metabolic syndrome and other risk factors for cardiovascular disease.

Methods

Secondary analysis of data from a nationwide cross-sectional survey for health examination at the time of transitioning from midlife to old age was performed. Multiple logistic regression models were used to estimate adjusted odds ratios and 95 % confidence intervals for gender differences among the Korean 66-year-old population with metabolic syndrome.

Results

Gender differences in metabolic syndrome components that contributed to the diagnosis of metabolic syndrome were identified. In males, the most common component was high blood sugar levels (87.5 %), followed by elevated triglyceride levels (83.5 %) and high blood pressure (83.1 %). In females, the most commonly identified component was elevated triglyceride levels (79.0 %), followed by high blood sugar levels (78.6 %) and high blood pressure (78.5 %). Gender differences for other risk factors for cardiovascular disease, including family history, health habits, and body mass index were observed.

Conclusions

Gender-specific public health policies and management strategies to prevent cardiovascular disease among the older adult population should be developed for Koreans undergoing the physiological transition to old age.

Women-specific factors to consider in risk, diagnosis and treatment of cardiovascular disease

In the era of individualized medicine, gaps in knowledge remain about sex-specific risk factors, diagnostic and treatment options that might reduce mortality from cardiovascular disease (CVD) and improve outcomes for both women and men. In this review, contributions of biological mechanisms involving the sex chromosomes and the sex hormones on the cardiovascular system will be discussed in relationship to the female-specific risk factors for CVD: hypertensive disorders of pregnancy, menopause and use of hormonal therapies for contraception and menopausal symptoms. Additionally, sex-specific factors to consider in the differential diagnosis and treatment of four prevalent CVDs (hypertension, stroke, coronary artery disease and congestive heart failure) will be reviewed with emphasis on areas where additional research is needed.

Defining Vitamin D Deficiency and Its Relationship to Hypertension in Postmenopausal Korean Women

BACKGROUND

Inconsistent results regarding the association between low vitamin D level and hypertension (HTN) have led to uncertainty in clinical practice as to the use of vitamin D cutoff value. The aims of this study were to investigate the association between vitamin D deficiency and HTN in postmenopausal women and to determine the clinically significant cutoff value for vitamin D deficiency.

METHODS

We analyzed data from the Korean National Health and Nutrition Examination Survey 5 database (4107 postmenopausal women, aged 50-79 years). The cutoff value for vitamin D deficiency was based on the changes in parathyroid hormone (PTH) level according to serum 25(OH)D value.

RESULTS

PTH levels were significantly higher in groups with serum 25(OH)D <15 ng/mL (p < 0.001). When a serum 25(OH)D value of 15 ng/mL was used as a cutoff value, 35.2% of the subjects were found to be vitamin D deficient. Although the association between 25(OH)D level <15 ng/mL and systolic blood pressure did not remain significant after adjusting for season (p = 0.30), multiple logistic regression analysis revealed that 25(OH)D level <15 ng/mL was an independent risk factor for HTN (adjusted odds ratio [OR] 1.285, 95% confidence interval [CI] 1.024-1.614, p = 0.031).

CONCLUSIONS

Using serum PTH level, we defined vitamin D deficiency as 25(OH)D <15 ng/mL in postmenopausal women. Vitamin D deficiency [25(OH)D <15 ng/mL] was a significant risk factor for HTN in postmenopausal women.

Aerobic Exercise Training Prevents the Onset of Endothelial Dysfunction via Increased Nitric Oxide Bioavailability and Reduced Reactive Oxygen Species in an Experimental Model of Menopause

OBJECTIVE

Previous studies have shown that estrogen deficiency, arising in postmenopause, promotes endothelial dysfunction. This study evaluated the effects of aerobic exercise training on endothelial dependent vasodilation of aorta in ovariectomized rats, specifically investigating the role of nitric oxide (NO) and reactive oxygen species (ROS).

METHODS

Female Wistar rats ovariectomized (OVX - n=20) or with intact ovary (SHAM - n=20) remained sedentary (OVX and SHAM) or performed aerobic exercise training on a treadmill 5 times a week for a period of 8 weeks (OVX-TRA and SHAM-TRA). In the thoracic aorta the endothelium-dependent and -independent vasodilation was assessed by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively. Certain aortic rings were incubated with L-NAME to assess the NO modulation on the ACh-induced vasodilation. The fluorescence to dihydroethidium in aortic slices and plasma nitrite/nitrate concentrations were measured to evaluate ROS and NO bioavailability, respectively.

RESULTS

ACh-induced vasodilation was reduced in OVX rats as compared SHAM (Rmax: SHAM: 86±3.3 vs. OVX: 57±3.0%, p<0.01). Training prevented this response in OVX-TRA (Rmax: OVX-TRA: 88±2.0%, p<0.01), while did not change it in SHAM-TRA (Rmax: SHAM-TRA: 80±2.2%, p<0.01). The L-NAME incubation abolished the differences in ACh-induced relaxation among groups. SNP-induced vasodilation was not different among groups. OVX reduced nitrite/nitrate plasma concentrations and increased ROS in aortic slices, training as effective to restore these parameters to the SHAM levels.

CONCLUSIONS

Exercise training, even in estrogen deficiency conditions, is able to improve endothelial dependent vasodilation in rat aorta via enhanced NO bioavailability and reduced ROS levels.