Maria Rivera

Cardiovascular responses to orthostatic stress in healthy altitude dwellers, and altitude residents with chronic mountain sickness

High altitude (HA) dwellers have an exceptionally high tolerance to orthostatic stress, and this may partly be related to their high packed cell and blood volumes. However, it is not known whether their orthostatic tolerance would be changed after relief of the altitude‐related hypoxia. Furthermore, orthostatic tolerance is known also to be influenced by the efficiency of the control of peripheral vascular resistance and by the effectiveness of cerebral autoregulation and these have not been reported in HA dwellers. In this study we examined plasma volume, orthostatic tolerance and peripheral vascular and cerebrovascular responses to orthostatic stress in HA dwellers, including some with chronic mountain sickness (CMS) in whom packed cell and blood volumes are particularly large. Eleven HA control subjects and 11 CMS patients underwent orthostatic stress testing, comprising head‐up tilting with lower body suction, at their resident altitude (4338 m) and at sea level. Blood pressure (Portapres), heart rate (ECG), brachial and middle cerebral artery blood velocities (Doppler) were recorded during the test. Plasma volumes were found to be similar in both groups and at both locations. Packed cell and blood volumes were higher in CMS patients than controls. All subjects had very good orthostatic tolerances at both locations, compared to previously published data in lowland dwellers. In CMS patients responses of forearm vascular resistance to the orthostatic stress, at sea level, were smaller than controls (P < 0.05). Cerebral blood velocity was less in CMS than in controls (P < 0.01) and, at sea level, it decreased more than the controls in response to head‐up tilting (P < 0.02). Cerebral autoregulation, assessed from the relationship between cerebral pressure and velocity, was also impaired in CMS patients compared to HA controls, when examined at sea level (P < 0.02). These results have shown that the good orthostatic tolerance seen in high altitude dwellers at altitude is also seen at sea level. There was no difference in orthostatic tolerance between CMS patients, with their exceptionally large blood volumes, and the HA controls. This may be because peripheral vascular and cerebrovascular responses (at least at sea level) are impaired in the CMS patients relative to HA controls. Thus, the advantage of the large blood volume may be offset by the smaller vascular responses.

The Relationship Between Socioeconomic Status and CV Risk Factors: The CRONICAS Cohort Study of Peruvian Adults

Background Variations in the distribution of cardiovascular disease and risk factors by socioeconomic status (SES) have been described in affluent societies, yet a better understanding of these patterns is needed for most low- and middle-income countries. Objective This study sought to describe the relationship between cardiovascular risk factors and SES using monthly family income, educational attainment, and assets index, in 4 Peruvian sites. Methods Baseline data from an age- and sex-stratified random sample of participants, ages ≥35 years, from 4 Peruvian sites (CRONICAS Cohort Study, 2010) were used. The SES indicators considered were monthly family income (n = 3,220), educational attainment (n = 3,598), and assets index (n = 3,601). Behavioral risk factors included current tobacco use, alcohol drinking, physical activity, daily intake of fruits and vegetables, and no control of salt intake. Cardiometabolic risk factors included obesity, elevated waist circumference, hypertension, insulin resistance, diabetes mellitus, low high-density lipoprotein cholesterol, and high triglyceride levels. Results In the overall population, 41.6% reported a monthly family income <US

Chronic Mountain Sickness

198, and 45.6% had none or primary education. Important differences were noted between the socioeconomic indicators: for example, higher income and higher scores on an asset index were associated with greater risk of obesity, whereas higher levels of education were associated with lower risk of obesity. In contrast, higher SES according to all 3 indicators was associated with higher levels of triglycerides. Conclusions The association between SES and cardiometabolic risk factors varies depending on the SES indicator used. These results highlight the need to contextualize risk factors by socioeconomic groups in Latin American settings.

The Relationship Between Socioeconomic Status and CV Risk Factors: The CRONICAS Cohort Study of Peruvian Adults: Investment in Global Health Research: A Public Private Partnership

More than 140 million people live above 2,500 m worldwide, about 80 million in Asia, and approximately 35 million in the Andean mountains. The greatest population density is located above 3,500 m. Chronic mountain sickness (CMS) is one of the most important high-altitude pathologies in the majority of mountainous regions of the world. Its hallmark sign is excessive erythrocytosis (EE). In more advanced and severe stages, high-altitude pulmonary hypertension (HAPH) appears frequently, with related remodeling of pulmonary arterioles and right ventricular hypertrophy.

Acetazolamide: a treatment for chronic mountain sickness.

Background Variations in the distribution of cardiovascular disease and risk factors by socioeconomic status (SES) have been described in affluent societies, yet a better understanding of these patterns is needed for most low- and middle-income countries. Objective This study sought to describe the relationship between cardiovascular risk factors and SES using monthly family income, educational attainment, and assets index, in 4 Peruvian sites. Methods Baseline data from an age- and sex-stratified random sample of participants, ages ≥35 years, from 4 Peruvian sites (CRONICAS Cohort Study, 2010) were used. The SES indicators considered were monthly family income (n = 3,220), educational attainment (n = 3,598), and assets index (n = 3,601). Behavioral risk factors included current tobacco use, alcohol drinking, physical activity, daily intake of fruits and vegetables, and no control of salt intake. Cardiometabolic risk factors included obesity, elevated waist circumference, hypertension, insulin resistance, diabetes mellitus, low high-density lipoprotein cholesterol, and high triglyceride levels. Results In the overall population, 41.6% reported a monthly family income <US

Spanish genetic admixture is associated with larger V̇o2 max decrement from sea level to 4,338 m in Peruvian Quechua

198, and 45.6% had none or primary education. Important differences were noted between the socioeconomic indicators: for example, higher income and higher scores on an asset index were associated with greater risk of obesity, whereas higher levels of education were associated with lower risk of obesity. In contrast, higher SES according to all 3 indicators was associated with higher levels of triglycerides. Conclusions The association between SES and cardiometabolic risk factors varies depending on the SES indicator used. These results highlight the need to contextualize risk factors by socioeconomic groups in Latin American settings.