sarcopenia is a geriatric syndrome primarily characterized by progressive and generalized loss of skeletal muscle mass . in addition , it is strongly associated with the aging process and can be exacerbated in the presence of pathological conditions ( e.g. , diabetes mellitus type ii ) [ 15 ] . sarcopenia negatively affects the autonomy and quality of life of older adults in different ways ( e.g. , by decreasing muscle strength and muscle power and increasing the risk of falls ) . in this respect , sarcopenia is associated with increased risk of falls and bone fractures , cognitive and muscle impairment , frailty , impaired performance of activities of daily living , loss of independency , and early death [ 15 ] . with regard to metabolic processes , older adults with lower skeletal muscle index ( smi ) can present hyperinsulinemia , dyslipidemia , high levels of glycosylated hemoglobin , and predisposition to prediabetic and metabolic syndrome conditions , particularly if smi is associated with obesity [ 7 , 8 ] . moreover , sarcopenic and nonsarcopenic older adults showed higher levels of insulin resistance and fasting glucose compared with nonsarcopenic older adults . although some studies demonstrated the relationship between morphofunctional and metabolic alterations due to sarcopenia , the effects of the decrease in skeletal muscle mass on the cardiovascular system are still inconclusive . recent studies have reported that alterations in the smi and increased arterial stiffness can negatively affect the cardiovascular system [ 911 ] . ochi and colleagues   indicated that older adults with lower thigh muscle cross - sectional area presented higher levels of risk factors for cardiovascular disease , including increased intima - media thickness and increased pulse - wave velocity . similarly , abbatecola and colleagues   observed higher pulse - wave velocity in american older adults with lower smi . pulse pressure ( pp ) is a simple and inexpensive measurement of arterial stiffness and is closely related to pulse - wave velocity [ 12 , 13 ] . furthermore , meta - analysis data indicate that increased pp is a good predictor of cardiovascular death and death from other causes in older people . therefore , in addition to the impairment of muscle function , autonomy , and metabolism caused by sarcopenia in older adults , recent studies showed a possible negative effect of sarcopenia on the cardiovascular system [ 4 , 9 ] . therefore , the aim of the present study was to evaluate the relationship between the sarcopenia index and hemodynamic dysfunctions in older women . this cross - sectional study evaluated 130 community - dwelling older women living in brazil . all volunteers were recruited from two specialized healthcare centers for older women : ( i ) a community center for older adults and ( ii ) institute reborn for seniors . in both centers , volunteers developed activities that involved predominantly the physical and cognitive domains . the physical activities offered were ( 1 ) a multimodal exercise program , which stimulates some physical capabilities ( i.e. , muscle strength , muscle power , and cardiorespiratory fitness ) in the same session of exercise ; these sessions lasted approximately 40 minutes and were performed in low - moderate intensity ; ( 2 ) water aerobics ; ( 3 ) folk dance ; and ( 4 ) yoga . participation in the present study involved the completion of all measurements after signing the informed consent form . this study was approved by the research ethics committee of the universidade de mogi das cruzes ( umc ) under protocol number 621 - 614 . this study was developed in accordance with the declaration of helsinki and according to resolution 196/96 of the national health council . the exclusion criteria were use of hormone replacement and/or psychotropic drugs , cardiovascular disease ( e.g. , acute myocardial infarction , stroke , peripheral arterial disease , and transient ischemic disease ) , pulmonary disease , neurological or psychiatric disease ( e.g. , parkinson 's or alzheimer 's disease ) , musculoskeletal disorders , and comorbidities associated with greater risk of falls . all clinical information ( i.e. , disease status , age , and drug therapy ) was obtained by reviewing the medical records of each subject . all subjects were instructed to refrain from physical exercise for 96 hours before the tests and to refrain from eating or drinking ( including water ) for 8 hours before the tests . all tests were conducted between 07:00 am and 10:00 am under a controlled temperature of 26c . a data acquisition system ( tanita innerscan 50v , tokyo , japan ) was used to measure the bioelectrical impedance . this system uses an electrical current to quantify the amount of intracellular and extracellular water in the body . the device has four electrodes : two are placed on the feet while the other two are placed on the hands of the volunteers . the device measures body mass index ( bmi ) , total body mass , total muscle mass , and percentage of fat mass . the bioelectrical impedance test allows the normalization of absolute muscle mass ( amm ) to height ( amm / height ) , which is denominated skeletal muscle mass index ( smi ) . older women classified into the first tertile ( < 15 , 68  kg / m ) were classified as sarcopenic . the procedures for the measurement of blood pressure were adapted from the vii joint national committee of high blood pressure ( jnc7 ) . in summary , older women remained in the sitting position in a comfortable chair for 15 minutes in a dark and quiet room . after this period , a cuff with the right size was placed approximately at the midpoint of the upper left arm ( heart level ) . an automatic , noninvasive and validated   arterial blood pressure monitor ( microlife - bp 3bt0a , microlife , widnau , switzerland ) was used to measure systolic blood pressure ( sbp ) , diastolic blood pressure ( dbp ) , and heart rate ( hr ) . the mean arterial pressure ( map ) , rate pressure product ( rpp ) , and pulse pressure ( pp ) were evaluated according to the following equations : map = [ sbp + ( 2  dbp)]/3 ; rpp = sbp  hr ; pp = sbp  dbp [ 12 , 19 ] . the size of the arm cuff was selected after measuring the arm circumference ( sanny , so paulo , brazil ) . muscle function was evaluated using the 3-meter walk speed test ( ws ) test . during the test , the volunteers were instructed to walk a distance of 5 meters at a normal cadence . to ensure this , the researcher requested the following :  please , walk as you were going to a supermarket or bakehouse . volunteers should remain with both feet on the starting line and counting started when one foot touched the 1-meter line and stopped when one foot touched the 4-meter line . the head physician recorded the pathological conditions but a specialist not affiliated to / outside the center made the pathologic diagnosis . the cofactors ( the number of drugs used by older women ( mean of drugs ) and smoking status ) were recorded by a head nurse after interviewing the participants . student 's t - test was used to compare quantitative variables and  was used to compare qualitative variables . after statistical analyses , it was verified that pp values were higher in the sarcopenic group and were significantly associated with smi ; subsequently , the correlation between smi and pp was investigated . stepwise linear regression was conducted to predict the best model to evaluate the association between smi and pp . multiple linear regression analysis was used to assess the significance of the proposed model . to assess whether the imm was a risk factor for pp sample size was determined on the basis of a population of 112.481 individuals and a confidence level of 95% . all analyses were conducted using the statistical package for the social sciences ( spss ; ibm , chicago , il , usa ) software version 20.0 . sarcopenic older women presented lower values of bmi , smi , and amm and lower muscle function but higher pp values compared with normal older women . pearson 's correlation was performed to assess possible associations between the cardiovascular variables and smi . our results showed a significantly negative association between smi and pp ( 0.25 ; p = 0.03 ) . moreover , adjustment for pathological conditions alone or in combination did not change the significance of the association ( hypertension ( 0.25 ; p = 0.05 ) ; diabetes mellitus type ii ( 0.25 ; p = 0.05 ) ; metabolic syndrome ( 0.25 ; p = 0.04 ) ; respiratory pathology ( 0.25 ; p = 0.05 ) ; and metabolic syndrome together with respiratory pathology ( 0.25 ; p = 0.04 ) ) . the findings on linear regression showed a significant r ( 0.49 ) for imm in relation to pp . however , multiple regression did not show significant results for any of the proposed models from stepwise linear regression . the odds ratio results indicate that older women with sarcopenia have three times increased risk ( 3.151 ) of having increased pp values compared with nonsarcopenic volunteers ( 1.3237.506 ( 95% confidence interval ) , p < 0.05 ) . the results of the present study indicate that sarcopenic older women have lower muscle function and higher pp levels compared with nonsarcopenic older women . these results were confirmed by using multilinear and linear regression and indicate a significantly negative association between smi and pp . furthermore , sarcopenic volunteers had a three times higher risk of having increased pp values compared with nonsarcopenic individuals . these findings are in accordance with those of other studies , which demonstrated a relationship between the sarcopenia index and cardiovascular alterations in older adults [ 4 , 911 , 20 ] . recently , han and colleagues   evaluated a large sample of older koreans ( n = 4.846 ) and observed a higher prevalence of hypertension in sarcopenic older adults compared with nonsarcopenic adults , regardless of the obesity level . in addition , nonobese sarcopenic older adults had a 1.5 times higher risk of presenting with hypertension compared with nonsarcopenic subjects . furthermore , other experiments have investigated whether sarcopenia could be associated with increased arterial stiffness , which can promote the development of hypertension as well as other cardiovascular and cerebrovascular diseases [ 12 , 2123 ] . it has also been demonstrated that increased pp levels are an important risk factor for coronary heart disease . similar to the results of the present study , other studies demonstrated an association between the degree of sarcopenia and arterial stiffness . these experiments observed that increase in sarcopenia was associated with increase in brachial - ankle pulse - wave velocity in japanese [ 7 , 11 , 20 ] and american older adults . furthermore , srikanthan and karlamangla   observed that the sarcopenia index was negatively associated with carotid intima - media thickness , suggesting a possible correlation with the formation of atherosclerotic plaques . in the present study , older women with lower smi showed higher odds ratio for higher pp levels compared with nonsarcopenic women . higher levels of brachial pp are associated with increased pulse - wave velocity , which is mainly due to the decrease large - vessel compliance . complications associated with higher pp values have been previously studied [ 2123 ] . in normotensive and hypertensive populations , higher pp was the most important determinant of the risk of death ( mainly due to cardiovascular complications ) [ 21 , 22 ] . for this reason , the possibility of using pp as a better predictor of cardiovascular death compared with other hemodynamic measurements ( e.g. , sbp and dbp ) has been recently considered . one of the limitations of the present study was the failure to assess the influence of pathological conditions on the association between smi and pp . however , no changes were observed in our results using pearson 's correlation and multilinear regression after adjusting for morbidities . diabetes type ii ( dmtii ) seems to enhance the loss of muscle mass primarily in individuals with uncontrolled glycemia [ 524 ] . furthermore , patients with low smi with and without dmtii demonstrated increased insulin resistance , hyperinsulinemia , and glycosylated hemoglobin levels compared with individuals with higher smi . recent evidence suggests a potential correlation between sarcopenia and dyslipidemia , which leads to hyperglycemia and ultimately metabolic syndrome . it is possible that the number of volunteers with pathologies was insufficient to evaluate the impact of each condition on the parameters evaluated . however , an advantage of the limited number of older people with illnesses is that , even in healthy older women , decreased muscle mass can impair the cardiovascular system . a possible mechanism that could explain the association between smi and higher pp levels in the sarcopenic group is increased chronic inflammation due to decreased muscle function , which can lead to physical inactivity . decreased muscle function resulted in higher levels of inflammatory markers in the blood of older adults . chronic low - grade inflammation is characterized by an increase in blood levels and gene expression of proinflammatory cytokines , which can  via paracrine and autocrine mechanisms  decrease the bioavailability of nitric oxide , increase arterial stiffness , increase the formation of atherosclerotic plaques , and promote endothelial dysfunction , which , in turn , can promote an increase in pp levels [ 2628 ] . on the other hand , the increase in muscle activity has been suggested as a mechanism that can inhibit chronic low - grade inflammation . it is known that bioactive proteins known as myokines ( e.g. , il-6 ) are produced by muscle fibers from muscle contraction [ 30 , 31 ] . myokines can inhibit the activity of proinflammatory cytokines ( e.g. , tnf- ) , thereby avoiding the deleterious effect of cytokines on the human body [ 25 , 27 ] . animal experiments showed that the increase in muscle activity by physical exercise could decrease the activity of tnf- in mice that overexpress this protein . in addition , the cytokine levels of volunteers who practiced physical exercise in the same day and who were stimulated to produce tnf- did not increase . however , the group that did not practice physical exercise had increased tnf- concentrations . in the present study , nonsarcopenic older women with improved muscle function possibly performed more muscle contractions , which led to the increased production of myokines , which in turn acted as a protective factor against chronic low - grade inflammation . individuals with low smi with and without diabetes demonstrated increased insulin resistance , hyperinsulinemia , and increased levels of glycosylated hemoglobin compared with individuals with higher smi , which was probably caused by decreased insulin levels in the target organ . furthermore , hyperinsulinemia due to insulin resistance can activate nfb , which is an important regulator of the production of proinflammatory cytokines . clearly , a synergistic effect of both mechanisms can not be discarded and is probably the best explanation . interestingly , the cofactors identified in the present study ( bmi , percentage of body fat , age , and muscle function ) had no effect on the association between smi and pp . other factors that can influence vascular homeostasis , such as nitric oxide , cholesterol , and low- and high - density lipoproteins , can be used to create a better model to investigate the relationship between smi and pp . moreover , studies involving study groups with specific pathologic conditions , such as dmt2 , hypertension , obesity , and metabolic syndrome , can help elucidate the impact of pathological conditions on muscle mass homeostasis and their effect on the cardiovascular system [ 5 , 8 ] . some of the limitations of the present study include ( i ) its cross - sectional design , which precluded the assessment of a time - effect relationship ; ( ii ) the limited number of volunteers enrolled , which can be partially explained by sample homogeneity , which contributed to a better understanding of the effect of sarcopenia on older women ; and ( iii ) the absence of biochemical measurements , which could have elucidated possible interacting mechanisms . however , to the best of our knowledge , this is the first study that addressed the relationship between low smi and changes in the arterial stiffness index in brazilian older women . the present study showed that older women with higher smi ( which is predominantly influenced by an active lifestyle ) presented lower pp levels and decreased cardiovascular risk whereas older women with a sarcopenic profile had a cardiovascular risk 3 times higher than that of nonsarcopenic women . therefore , beneficial therapies , such as strength exercise , can help increase or maintain muscle mass and consequently improve the quality of life of older people .
introduction . 
 sarcopenia is a geriatric syndrome associated with impairment of muscle function , metabolism , and cognition in older women . 
 recent studies have shown a relationship between changes in muscle mass and the cardiovascular system . however , this relationship has not been fully elucidated . methods . 
 one hundred and thirty community - dwelling brazilian older women ( 65.4  6.3 years ) were recruited to participate in this study . 
 data on body composition ( via bioelectrical impedance measurements ) , cardiovascular parameters ( using an automatic and noninvasive monitor ) , and muscle function ( using a 3-meter gait speed test ) were measured . results . 
 sarcopenic older women ( n = 43 ) presented higher levels of pulse pressure ( pp ) ( 60.3  2.6  mmhg ) and lower muscle function ( 0.5  0.0  m / s ) compared with nonsarcopenic subjects ( n = 87 ) ( 53.7  1.5  mmhg ; 0.9  0.0  m / s ) ( p < 0.05 ) . 
 linear regression analysis demonstrated a significantly negative association between skeletal muscle index ( smi ) and pp levels (  = 226 , p < 0.05 ) . 
 furthermore , sarcopenic older women showed a 3.1-fold increased risk of having higher pp levels compared with nonsarcopenic women ( ic = 1.3237.506 ) ( p < 0.05 ) . 
 conclusion . 
 sarcopenic older women showed lower muscle function and higher cardiovascular risk due to increased pp levels compared with nonsarcopenic subjects .