Age and sex disparities in blood pressure control and therapeutic inertia: Impact of a quality improvement program.

Objective: Hypertension quality improvement programs reduce uncontrolled blood pressure (BP) but impact may differ by sex and age. Methods: This study examined uncontrolled BP, defined as a BP ≥ 140/90 mmHg, and therapeutic inertia, defined as absence of medication initiation or escalation during visits with uncontrolled BP, by sex and by age group (19-40, 41-65, 66-75, and 76+ years) during a 12 month follow-up period among 21, 861 patients with hypertension and ≥ two visits in primary care clinics enrolled in the American Medical Association (AMA) Measure Accurately, Act Rapidly, and Partner with Patients (MAP) BP hypertension quality improvement program. Results: The mean age was 64.8 years (standard deviation [SD 12.8]) and ranged from 19 to 87 years; 53.6% were female. In age groups 19-40, 41-65, 66-75, 76-87 years, uncontrolled BP at the first clinic visit was present in 51.5%, 42.5%, 37.5% and 36.6% of males, respectively, and in 40.0%, 38.0%, 36.0% and 39.6% of females, respectively. Based on vital signs at the first vs. last clinic visit, the proportion of patients with uncontrolled BP in age groups 19-40, 41-65, 66-75 years declined by 19.4%, 13.5%, 10.1% and 8.7% in males, respectively, and 14.4%, 12.5%, 9.3%, and 8.4%, among females, respectively. Therapeutic inertia ranged from 66.5% and 75.9% of clinic visits among males and females age 19-40 years, to 85.6% and 84.9% of clinic visits among males and females age 76-87 years, respectively. The proportion of clinic visits with therapeutic inertia was lower among males vs. females across all age groups until age 76-87 years. Conclusion: A quality improvement program improves BP control but declines in uncontrolled BP are larger and therapeutic inertia is lower for younger vs. older age groups and for males vs. females. More interventions are needed to reduce sex and age disparities in hypertension management.

Medical Nutrition Therapy for Chronic Kidney Disease: Low Access and Utilization.

CKD affects approximately half of US adults aged 65 years and older and accounts for almost 1 out of every 4 dollars of total Medicare fee-for-service spending. Efforts to prevent or slow CKD progression are urgently needed to reduce the incidence of kidney failure and reduce health care expenditures. Current CKD care guidelines recommend medical nutrition therapy (MNT), a personalized, evidence-based application of the Nutrition Care Process (assessment, intervention, diagnosis, and monitoring and evaluation) provided by registered dietitian nutritionists (RDNs) to help slow CKD progression, improve quality of life, and delay kidney failure. MNT is covered by Medicare Part B and most private insurances with no cost sharing. Despite recommendations that patients with CKD receive MNT and insurance coverage for MNT, utilization remains low. This article demonstrates low utilization of MNT and inadequate numbers of RDNs and RDNs who are board certified in renal nutrition relative to the estimated number of Medicare eligible adults with self-reported diagnosed CKD by state, with noted disparities across states. We discuss interventions to increase MNT utilization, such as improving MNT reimbursement, augmenting accessibility of RDNs via telenutrition services and increasing health care provider promotion of MNT and referral to MNT to optimize CKD outcomes.

Realizing the Goals of the Advancing American Kidney Health Initiative: Toward a Better Future for Kidney Disease Research Funding.

The Executive Order on Advancing American Kidney Health aimed to slow the progression of kidney disease, increase access to kidney transplantation, and expand home dialysis. In order to support the kidney health strategy laid out by the Advancing American Kidney Health, the National Institutes of Health, the National Institute of Diabetes, and Digestive, and Kidney Diseases, as well as other funding agencies must dedicate robust research funding to kidney disease. Currently, federal research investment for kidney health is less than 1% of Medicare fee-for-service expenditures for Americans with kidney disease. To address disparities in federal research funding, nephrology organizations are working together to advocate for increased federal commitment to kidney disease research. Underfunding of kidney disease research impedes scientific opportunities and innovation and prevents the collaboration of young investigators with research faculty that can accelerate the exodus of talent within the nephrology research workforce. This review provides an overview of the current state of federal research funding for kidney disease within the United States. In addition, we discuss ongoing advocacy efforts and programs that aim to increase federal funding for kidney-related research and accelerate the development of new and better therapies.

Age and sex disparities in hypertension control: The multi-ethnic study of atherosclerosis (MESA).

OBJECTIVE: Determine sex differences in hypertension control by age group in a diverse cohort of adults age 45-84 years at baseline followed for an average of 12 years. METHODS: The Multi-Ethnic Study of Atherosclerosis enrolled 3213 men and 3601 women from six communities in the U.S. during years 2000-2002 with follow-up exams completed approximately every two years. At each exam, resting blood pressure (BP) was measured in triplicate, and the last two values were averaged. Hypertension was defined as a BP ≥ 140/90 mmHg and/or use of antihypertensive medications. Hypertension control was defined as a BP < 140/90 mmHg and in separate analyses as < 130/90 mmHg. Generalized linear mixed effects models with a binomial function were used to calculate the odds of hypertension control by age group (45-64,75-74, 75+) at a given exam and by sex, while accounting for the intra-individual correlation, and adjustment for demographics, co-morbidities, smoking, alcohol use, education and site among participants with hypertension at any of the first five exams. RESULTS: At baseline, mean age was 64.1 (9.1 [SD]) years, 48.0% were men, and race/ethnicity was Non-Hispanic white in 34.1%, 10.1% Chinese, 35.1% Non-Hispanic Black and 20.7% Hispanic. Average SBP was lower while average DBP was higher among men vs. women at each exam. Adjusted odds ratios of hypertension control defined as BP < 140/90 mmHg among men vs. women was 0.89 (95% CI 0.67, 1.19) for age 45-64 years, 1.37 (95% CI 1.04, 1.81) for age 65-74 years and 2.08 (95% CI 1.43, 3.02) for age 75+ years. When defined as < 130/80 mmHg, adjusted odds of hypertension control among men vs. women was 0.60 (OR 0.60; 95% CI 0.46, 0.79) at age 45-64 years, 1.01 (OR 1.01; 95% CI 0.77, 1.31) at age 65-74 years and 1.71 (95% CI 1.19, 2.45) at age 75+ years. CONCLUSION: Sex disparities in hypertension control increase with advancing age and are greatest among adults age 75+ years.

Kidney-Related Research in the United States: A Position Statement From the National Kidney Foundation and the American Society of Nephrology.

Kidney disease is an important US public health problem because it affects over 37 million Americans, and Medicare expenditures for patients with chronic kidney disease now alone exceed $130 billion annually. Kidney disease is characterized by strong racial, ethnic, and socioeconomic disparities, and reducing kidney disease incidence will positively impact US health disparities. Due to the aging of the US population and an unabated obesity epidemic, the number of patients receiving treatment for kidney failure is anticipated to increase, which will escalate kidney disease health expenditures. The historical and current investment in kidney-related research via the National Institute of Diabetes and Digestive and Kidney Diseases has severely lagged behind ongoing expenditures for kidney disease care. Increasing research investment will identify, develop, and increase implementation of interventions to slow kidney disease progression, reduce incidence of kidney failure, enhance survival, and improve quality of life. This perspective states the urgent reasons why increasing investment in kidney-related research is important for US public health. The National Kidney Foundation and the American Society of Nephrology are working together to advocate for increased funding for the National Institute of Diabetes and Digestive and Kidney Diseases. The long-term goal is to reduce the burden of kidney disease in the US population and improve the quality of life of patients living with kidney disease.

Association of Educational Attainment With Incidence of CKD in Young Adults.

INTRODUCTION: Chronic kidney disease (CKD) is greatly affected by social determinants of health. Whether low educational attainment is associated with incident CKD in young adults is unclear. METHODS: We evaluated the association of education with incident CKD in 3139 Coronary Artery Risk Development in Young Adults participants. We categorized education into low (high school and less), medium (college), and high (master's and professional studies) groups. Incident CKD was defined as new development of estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2 or urine albumin to creatinine ratio (ACR) ≥30 mg/g. Change in eGFR over 20 years was a secondary outcome. RESULTS: At baseline, mean age was 35.0 ± 3.6 years, 47% were Black, and 55% were women. Participants with lower educational attainment were less likely to have high income and health insurance and to engage in a healthy lifestyle. Over 20 years, 407 participants developed CKD (13%). Compared with individuals with low educational attainment, those with medium and high educational attainment had an unadjusted hazard ratios for CKD of 0.79 (95% confidence interval [CI] 0.65-0.97) and 0.44 (95% CI, 0.30-0.63), respectively. This association was no longer significant after adjusting for income, health insurance, lifestyle, and health status. Low educational attainment was significantly associated with a change in eGFR in crude and adjusted analyses, although the association was attenuated in the multivariable models (low: -0.83 [95% CI, -0.91 to -0.75], medium: -0.80 (95% CI, -0.95 to -0.64), and high: -0.70 (95% CI, -0.89 to -0.52) ml/min per 1.73 m2 per yr). CONCLUSIONS: Health care access, lifestyle, and comorbid conditions likely help explain the association between low educational attainment and incident CKD in young adults.

Prevalence, Awareness, and Treatment of Hypertension in Hispanics/Latinos With CKD in the Hispanic Community Health Study/Study of Latinos.

RATIONALE & OBJECTIVE: Lower rates of hypertension awareness, treatment, and control have been observed in Hispanics/Latinos compared with non-Hispanic whites. These factors have not been studied in Hispanics/Latinos with chronic kidney disease (CKD). We sought to describe the prevalence, awareness, treatment, and control of hypertension in Hispanic/Latino adults with CKD. STUDY DESIGN: Cross-sectional cohort. SETTING & PARTICIPANTS: US.Hispanics/Latinos aged 18 to 74 years enrolled in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) with CKD. Comparisons were made with the National Health and Nutrition Examination Survey (NHANES) 2007 to 2010. EXPOSURE: CKD was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m2 or urinry albumin-creatinine ratio ≥ 30 mg/g creatinine. OUTCOMES: Hypertension was defined as systolic blood pressure (BP) ≥ 140 or diastolic BP ≥ 90 mm Hg or use of antihypertensives. For hypertension control, 2 thresholds were examined: <140/90 and <130/80 mm Hg. RESULTS: The prevalence of hypertension was 51.5%; among those with hypertension, hypertension awareness and treatment were present in 78.1% and 70.4%, respectively. A low prevalence of BP control was observed (32.6% with BP < 140/90 mm Hg; 17.9% with BP < 130/80 mm Hg). Health insurance coverage was associated with higher odds of BP < 140/90 mm Hg (OR, 1.98; 95% CI, 1.15-3.43). Compared with non-Hispanic whites with CKD in NHANES, HCHS/SOL participants with CKD had a lower prevalence of hypertension but a lower rate of BP control (32.6% vs 48.6% for BP < 140/90 mm Hg). LIMITATIONS: Use of a single measurement of creatinine, cystatin C, and urinary albumin excretion to define CKD. Single-visit measurement of BP. CONCLUSIONS: Hispanics/Latinos with CKD residing in the United States have very low rates of BP control. The association of health insurance coverage with hypertension control suggests that improved access to health care may improve outcomes for this growing population.

Chronic Kidney Disease Awareness and Longitudinal Health Outcomes: Results from the REasons for Geographic And Racial Differences in Stroke Study.

BACKGROUND: The majority of people with chronic kidney disease (CKD) are unaware of their kidney disease. Assessing the clinical significance of increasing CKD awareness has critical public health and healthcare delivery implications. Whether CKD awareness among persons with CKD is associated with longitudinal health behaviors, disease management, and health outcomes is unknown. METHODS: We analyzed data from participants with CKD in the REasons for Geographic And Racial Differences in Stroke study, a national, longitudinal, population-based cohort. Our predictor was participant CKD awareness. Outcomes were (1) health behaviors (smoking avoidance, exercise, and nonsteroidal anti-inflammatory drug use); (2) CKD management indicators (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, statin use, systolic blood pressure, fasting blood glucose, and body mass index); (3) change in estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (UACR); and (4) health outcomes (incident end-stage kidney disease [ESKD], coronary heart disease [CHD], stroke, and death). Logistic and linear regressions were used to examine the association of baseline CKD awareness with outcomes of interest, adjusted for CKD stage and participant demographic and clinical factors. RESULTS: Of 6,529 participants with baseline CKD, 285 (4.4%) were aware of their CKD. Among the 3,586 participants who survived until follow-up (median 9.5 years), baseline awareness was not associated with subsequent odds of health behaviors, CKD management indicators, or changes in eGFR and UACR in adjusted analyses. Baseline CKD awareness was associated with increased risk of ESKD (adjusted hazard ratio [aHR] 1.44; 95% CI 1.08-1.92) and death (aHR 1.18; 95% CI 1.00-1.39), but not with subsequent CHD or stroke, in adjusted models. CONCLUSIONS: Individuals aware of their CKD were more likely to experience ESKD and death, suggesting that CKD awareness reflects disease severity. Most persons with CKD, including those that are high-risk, remain unaware of their CKD. There was no evidence of associations between baseline CKD awareness and longitudinal health behaviors, CKD management indicators, or eGFR decline and albuminuria.

Non-dialysis dependent chronic kidney disease is associated with high total and out-of-pocket healthcare expenditures.

BACKGROUND: Previous studies have documented the high costs of non-dialysis dependent chronic kidney disease (CKD) but out-of-pocket healthcare expenditures remain poorly explored. This study described total direct and out-of-pocket expenditures for adults with non-dialysis dependent CKD and compared expenditures with those for cancer or stroke. METHODS: This study used data from the 2011-2013 Medical Expenditure Panel Survey, a national survey of healthcare expenditures in the U.S. POPULATION: Expenditures were determined for adults with the following chronic diseases: CKD defined by 585 ICD9 codes (n = 52), cancer (colon, breast or bronchus/lung) (n = 870), or stroke (n = 1104). These represent adults who were aware of their conditions or visited a healthcare provider for the condition during the study period. Generalized linear models were used to estimate the marginal effects of CKD, cancer or stroke on adjusted expenditures compared to adults without CKD, cancer or stroke (n = 72,241) while controlling for demographics and co-morbidities and incorporating the sample weights of the complex survey design. RESULTS: The mean age for group with CKD, cancer or stroke was 65.5, 66.1, and 68.2 years, respectively, while mean age for group without CKD, cancer or stroke was 47.8 years. Median values of total direct and out of pocket healthcare expenditures ranged from as high as $12,877 (Interquartile Range [IQR] $5031-$19,710) and $1439 ($688-$2732), respectively, with CKD, to as low as $1189 (IQR $196-$4388) and $226 (IQR $20-$764) in the group without CKD, cancer or stroke. After adjusting for demographics and comorbidities, the adjusted difference in total direct healthcare expenditures was $4746 (95% CI $1775-$7718) for CKD, $8608 (95% CI $6167-$11,049) for cancer and $5992 (95% CI $4208-$7775) for stroke vs. group without CKD, cancer or stroke. Adjusted difference in out-of-pocket healthcare expenditures was highest for adults with CKD ($760; 95% CI 0-$1745) and was larger than difference noted for cancer ($419; 95% CI 158-679) or stroke ($246; 95% CI 87-406) relative to group without CKD, cancer or stroke. CONCLUSIONS: Total and out of pocket health expenditures for adults with non-dialysis dependent CKD are high and may be equal to or higher than expenditures incurred by adults with cancer or stroke.

Fibroblast Growth Factor-23 (FGF-23) Levels Differ Across Populations by Degree of Industrialization.

CONTEXT: Compensatory increases in fibroblast growth factor 23 (FGF23) with increasing phosphate intake may adversely impact health. However, population and clinical studies examining the link between phosphate intake and FGF23 levels have focused mainly on populations living in highly industrialized societies in which phosphate exposure may be homogenous. OBJECTIVE: The objective of the study was to contrast dietary phosphate intake, urinary measures of phosphate excretion, and FGF23 levels across populations that differ by the level of industrialization. DESIGN: This was a cross-sectional analysis of three populations. SETTING: The study was conducted in Maywood, Illinois; Mahé Island, Seychelles; and Kumasi, Ghana. PARTICIPANTS: Adults with African ancestry aged 25-45 years participated in the study. MAIN OUTCOME: FGF23 levels were measured. RESULTS: The mean age was 35.1 (6.3) years and 47.9% were male. Mean phosphate intake and fractional excretion of phosphate were significantly higher in the United States vs Ghana, whereas no significant difference in phosphate intake or fractional excretion of phosphate was noted between the United States and Seychelles for men or women. Overall, median FGF23 values were 57.41 RU/mL (interquartile range [IQR] 43.42, 75.09) in the United States, 42.49 RU/mL (IQR 33.06, 55.39) in Seychelles, and 33.32 RU/mL (IQR 24.83, 47.36) in Ghana. In the pooled sample, FGF23 levels were significantly and positively correlated with dietary phosphate intake (r = 0.11; P < .001) and the fractional excretion of phosphate (r = 0.13; P < .001) but not with plasma phosphate levels (r = -0.001; P = .8). Dietary phosphate intake was significantly and positively associated with the fractional excretion of phosphate (r = 0.23; P < .001). CONCLUSION: The distribution of FGF23 levels in a given population may be influenced by the level of industrialization, likely due to differences in access to foods preserved with phosphate additives.

Validation of an Albuminuria Self-assessment Tool in the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVE: We previously developed an 8-item self-assessment tool to identify individuals with a high probability of having albuminuria. This tool was developed and externally validated among non-Hispanic Whites and non-Hispanic Blacks. We sought to validate it in a multi-ethnic cohort that also included Hispanics and Chinese Americans. DESIGN: This is a cross-sectional study. SETTING: Data were collected using standardized questionnaires and spot urine samples at a baseline examination in 2000-2002. The 8 items in the self-assessment tool include age, race, gender, current cigarette smoking, history of diabetes, hypertension, or stroke, and self-rated health. PARTICIPANTS: Of 6,814 community-dwelling adults aged 45-84 years participating in the Multi-Ethnic Study of Atherosclerosis (MESA), 6,542 were included in the primary analysis. MAIN OUTCOME MEASURES: Albuminuria was defined as urine albumin-to-creatinine ratio ≥ 30 mg/g at baseline. RESULTS: Among non-Hispanic Whites, non-Hispanic Blacks, Hispanics, and Chinese Americans, the prevalence of albuminuria was 6.0%, 11.3%, 11.6%, and 10.8%, respectively. The c-statistic for discriminating participants with and without albuminuria was .731 (95% CI: .692, .771), .728 (95% CI: .687, .761), .747 (95% CI: .709, .784), and .761 (95% CI: .699, .814) for non-Hispanic Whites, non-Hispanic Blacks, Hispanics, and Chinese Americans, respectively. The self-assessment tool over-estimated the probability of albuminuria for non-Hispanic Whites and Blacks, but was well-calibrated for Hispanics and Chinese Americans. CONCLUSIONS: The albuminuria self-assessment tool maintained good test characteristics in this large multi-ethnic cohort, suggesting it may be helpful for increasing awareness of albuminuria in an ethnically diverse population.

Depression in the US population during the time periods surrounding the great recession.

OBJECTIVE: To determine whether the time periods surrounding the 2008 US economic downturn were accompanied by an increase in prevalence of depression in the US adult population. METHOD: We used data from the 24,182 adults aged ≥ 18 years who participated in the National Health and Nutrition Examination Survey during 2005-2012. A cross-sectional analysis was performed at each time period to determine prevalence of major and other depression as assessed by standardized questionnaires based on 9 criteria for major depressive episodes defined by DSM-IV. RESULTS: The demographic characteristics of the US population were similar across time periods except for the percentage of adults living in poverty, which increased from 26.43% during 2005-2006 to 33.46% during 2011-2012. The prevalence of major depression increased from 2.33% (95% CI, 1.64%-3.01%) during 2005-2006 to 3.49% (95% CI, 2.84%-4.03%) in 2009-2010 to 3.79% (95% CI, 3.01%-4.57%) in 2011-2012. Prevalence of other depression increased from 4.10% (95% CI, 3.37%-4.88%) in 2005-2006 to 4.79% (95% CI, 4.10%-5.44%) in the 2009-2010 period but then declined to 3.68% (95% CI, 2.84%-4.48%) in the 2011-2012 time period (P = .4). After adjustment for the distribution of age, sex, race/ethnicity, education, insurance status, and poverty status in the US adult noninstitutionalized population, each 2-year period after the 2005-2006 time period was associated with a 0.4% increase in major depression prevalence (P < .001). No significant differences in other depression prevalence were noted by time period (P = .6). CONCLUSIONS: The time periods surrounding the recent economic recession were accompanied by a significant and sustained increase in major depression prevalence in the US population. It is plausible that the recession, given its strong, persistent, and negative effects on employment, job and housing security, and stock investments, contributed to the sustained increase in prevalence of major depression in the US population, but other factors associated with the recession time period could have played a role. The impact of the economic downturn on depression prevalence should be considered when formulating future policies and programs to promote and maintain the health of the US population.

Trajectories of kidney function decline in young black and white adults with preserved GFR: results from the Coronary Artery Risk Development in Young Adults (CARDIA) study.

BACKGROUND: Strong racial discrepancies in end-stage renal disease exist. Whether there are race differences in kidney function loss in younger healthy persons is not well established. STUDY DESIGN: Longitudinal. SETTING & PARTICIPANTS: 3,348 black and white adults with at least 2 measurements of cystatin C-based estimated glomerular filtration rate (eGFRcys) at scheduled Coronary Artery Risk Development in Young Adults (CARDIA) examinations (years 10, 15, and 20). PREDICTOR: Race. OUTCOMES & MEASUREMENTS: We used linear mixed models to examine race differences in annualized rates of eGFRcys decline, adjusting for age, sex, lifetime exposure to systolic blood pressure >120 mm Hg, diabetes, and albumin-creatinine ratio. We used Poisson regression to compare racial differences in rapid decline (eGFRcys decline >3% per year) by study period (10-15 years after baseline examination [defining period 1] and >15-20 years after baseline examination [defining period 2]). RESULTS: Mean age was 35 ± 3.6 (SD) years, and mean eGFRcys was 110 ± 20 mL/min/1.73 m² for blacks and 104 ± 17 mL/min/1.73 m² for whites at baseline. For both blacks and whites, eGFRcys decline was minimal at younger ages (<35 years) and eGFRcys loss accelerated at older ages. However, acceleration of eGFRcys decline occurred at earlier ages for blacks than whites. Blacks had somewhat faster annualized rates of decline compared with whites, but differences were attenuated after adjustment in period 1 (0.13 mL/min/1.73 m² per year faster; P = 0.2). In contrast, during period 2, blacks had significantly faster annualized rates of decline, even after adjustment (0.32 mL/min/1.73 m² per year faster; P = 0.003). The prevalence of rapid decline was significantly higher for blacks versus whites, with prevalence rate ratios of 1.31 (95% CI, 1.04-1.63) for period 1 and 1.24 (95% CI, 1.09-1.41) for period 2. Differences were attenuated after full adjustment: adjusted prevalence rate ratios were 1.20 (95% CI, 0.95-1.49) for period 1 and 1.10 (95% CI, 0.96-1.26) for period 2. LIMITATIONS: No measured GFR. CONCLUSIONS: eGFRcys decline differs by race at early ages, with faster annualized rates of decline for blacks. Future studies are required to explain the observed differences.

Ethnicity, energy expenditure and obesity: are the observed black/white differences meaningful?

PURPOSE OF REVIEW: Recent studies have suggested that black individuals have lower energy expenditure than whites. Many investigators hypothesized that this is why black women experience higher rates of obesity than white women. These findings initiated much research on race as a primary biological determinant of obesity and energy expenditure as a potential pathway. Race is a difficult construct to use in biomedical research. RECENT FINDINGS: Recent findings have included: an explanation for the lower resting energy expenditure observed among black adults, data showing that relative resting energy expenditure may not be a significant predictor of weight change in African-origin populations, and inconsistent data on the role of activity energy expenditure as a determinant of children's weight change. SUMMARY: The data suggest that black individuals have lower resting energy expenditure and possibly activity energy expenditure than white individuals. The lower resting energy expenditure is probably caused by a smaller mass of high metabolically active organs. It is unlikely that increased weight gain is associated with lower resting energy expenditure or activity among blacks, because no association has been found within populations. Clinically, it is important to focus on personal modifiable risk factors, e.g., energy intake and physical activity levels.

Association between blood pressure and resting energy expenditure independent of body size.

Obesity is an important risk factor for hypertension; however, the pathway through which it raises blood pressure (BP) is poorly understood. Body size is also the primary determinant of energy expenditure, and we therefore examined the joint relationship of energy expenditure and body size to blood pressure. Resting energy expenditure (REE) was measured using respiratory gas exchange in population-based samples of 997 Nigerians and 452 African Americans. In a third sample of 118 individuals, nonresting energy expenditure (ie, physical activity) was measured in addition to REE. The univariate correlation between REE and BP ranged from 0.10 to 0.22 in the 3 samples (P<0.001). In multivariate models, adiposity, whether defined by body mass, fat mass, or leptin, was no longer associated with BP, while REE remained highly significant (P<0.001). The REE-BP association also persisted after adjustment for physical activity measured with doubly labeled water. The odds ratio for hypertension among persons in the highest quartile versus the lowest quartile of REE, after adjustment for body size, was 1.7. This relationship was not the result of hypertension among the obese, because it did not vary across the range of BMI and was the same in lean Nigerians as in obese Americans. These data suggest that metabolic processes represented by REE may mediate the effect of body size on BP. The interrelationship of REE with sympathetic tone, transmembrane ion exchange, or other metabolic processes that determine energy costs at rest could provide physiological explanations for this observation.