Biomedical subjects
Publications and source records attributed to Michelle E Tarver-Carr.
A young woman with headaches displayed ophthalmoscopic features suggestive of papilledema. MRI showed no intracranial abnormalities but demonstrated oblique insertion of the optic nerve into the left globe and posterior nasal flattening of the left globe, features consistent with congenitally tilted optic discs. This is the second report to show that orbital MRI can demonstrate this phenomenon.
CONTEXT: Chronic kidney disease is a growing public health problem. Screening for early identification could improve health but could also lead to unnecessary harms and excess costs. OBJECTIVE: To assess the value of periodic, population-based dipstick screening for early detection of urine protein in adults with neither hypertension nor diabetes and in adults with hypertension. DESIGN, SETTING, AND POPULATION: Cost-effectiveness analysis using a Markov decision analytic model to compare a strategy of annual screening with no screening (usual care) for proteinuria at age 50 years followed by treatment with an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin II-receptor blocker (ARB). MAIN OUTCOME MEASURE: Cost per quality-adjusted life-year (QALY). RESULTS: For persons with neither hypertension nor diabetes, the cost-effectiveness ratio for screening vs no screening (usual care) was unfavorable (282 818 dollars per QALY; incremental cost of 616 dollars and a gain of 0.0022 QALYs per person). However, screening such persons beginning at age 60 years yielded a more favorable ratio (53 372 dollars per QALY). For persons with hypertension, the ratio was highly favorable (18 621 dollars per QALY; incremental cost of 476 dollars and a gain of 0.03 QALYs per person). Cost-effectiveness was mediated by both chronic kidney disease progression and death prevention benefits of ACE inhibitor and ARB therapy. Influential parameters that might make screening for the general population more cost-effective include a greater incidence of proteinuria, age at screening (53 372 dollars per QALY for persons beginning screening at age 60 years), or lower frequency of screening (every 10 years: 80 700 dollars per QALY at age 50 years; 6195 dollars per QALY at age 60 years; and 5486 dollars per QALY at age 70 years). CONCLUSIONS: Early detection of urine protein to slow progression of chronic kidney disease and decrease mortality is not cost-effective unless selectively directed toward high-risk groups (older persons and persons with hypertension) or conducted at an infrequent interval of 10 years.
BACKGROUND: Persons with chronic kidney disease who need kidney replacement therapy to sustain life have health insurance. We examined whether young adults, women, blacks, less-educated persons, the poor, and persons residing in less populated areas receive treatment when health insurance is no longer a barrier. METHODS: We conducted a case-control study nested in the Second National Health and Nutrition Examination Survey Mortality Study. Cases were persons treated with kidney replacement therapy determined by linkage to the end-stage renal disease treatment registry. Controls were untreated persons with kidney disease who died not appearing in the registry. RESULTS: During 12 to 16 years, 44 persons developed treated disease, and 145 persons, untreated disease. After adjustment for sex, age, education, population of residential area, and comorbid conditions in logistic regression analysis, younger versus older age and living in a highly populated versus less populated area were both independently associated with treatment (relative odds of treatment, 5.57; 95% confidence interval, 1.72 to 18.0; and 4.33; 95% confidence interval, 2.09 to 8.97, respectively). Race, sex, education, and poverty were not associated with less treatment. CONCLUSION: We found no disparity in life-saving chronic kidney disease treatment with regard to race or socioeconomic status in this population-based study. Less receipt of treatment by older adults may reflect greater comorbid disease or choices made by persons or their providers. Strategies to render treatment in less populated areas, including incentives to deliver care to such areas, should be encouraged.
BACKGROUND: Atherosclerosis and chronic kidney disease (CKD) share several common antecedents. However, the association between inflammatory markers and incident CKD is unknown. METHODS: We determined risk for incident CKD, defined by treatment for kidney failure or death related to kidney disease, in 9,250 US adults aged 30 to 74 years who participated in the Second National Health and Nutrition Examination Survey (NHANES II), a nationally representative prospective cohort study with 17 years of follow-up. RESULTS: After adjusting for age, race, sex, blood pressure, smoking, and body mass index, there was a graded positive association with increasing total white blood cell (WBC) count and risk for CKD (P for trend < 0.001; relative hazard (RH) highest versus lowest quartile, 2.34; 95% confidence interval [CI], 1.30 to 4.19). This association remained statistically significant after adjusting further for the presence of diabetes and cardiovascular disease at baseline (RH, 2.01; 95% CI, 1.11 to 3.65). A similarly strong and graded association with incident CKD was observed for hypoalbuminemia after adjusting for age, race, sex, blood pressure, smoking, and body mass index (P for trend = 0.02; RH lowest versus highest quartile, 1.91; 95% CI, 0.89 to 4.07) and additionally adjusting for the presence of diabetes and cardiovascular disease at baseline (P for trend = 0.02; RH lowest versus highest, 2.05; 95% CI, 0.96 to 4.39). CONCLUSION: In a nationally representative sample of US adults, elevated WBC count and hypoalbuminemia were associated with future risk for CKD. These results support the hypothesis that systemic inflammation is an independent risk factor for CKD.
BACKGROUND: Some lifestyle behaviors and obesity are risk factors for vascular disease, but their relation to kidney disease is uncertain. METHODS: To determine whether physical inactivity, smoking, alcohol drinking and obesity are associated with the risk of chronic kidney disease, we examined data from a nonconcurrent cohort study of 9,082 U.S. adults, aged 30-74 years, who participated in the second National Health and Nutrition Examination Survey (NHANES II) from 1976 through 1980. By linking the NHANES II Mortality Study with the Medicare end-stage kidney disease registry, we identified 189 incident cases of either treated end-stage kidney disease or chronic kidney disease-related death through 1992. RESULTS: The risk of chronic kidney disease was related to physical inactivity both with and without adjustment for age, sex, race and body-mass index. The adjusted relative risk (RR) of moderately active versus very active persons was 1.2 (95% confidence interval = 0.7-1.8), and of inactive versus very active was 2.2 (1.3-3.8). Risk was also related to smoking; the RR in smokers of 1-20 cigarettes a day versus never smokers was 1.2 (0.7-2.3), and in smokers of more than 20 cigarettes a day, the RR was 2.3 (1.3-4.2). The RR in morbidly obese (body-mass index >/= 35 kg/m2) compared with normal weight persons was 2.3 (1.1-4.9), but risk was not increased for those classified as overweight or obese. Obesity risk appeared largely mediated by diabetes and hypertension, whereas physical inactivity risk was only partly explained by these factors, and smoking risk was independent of them. Alcohol consumption was not related to chronic kidney disease. CONCLUSIONS: These data suggest that physical inactivity, smoking and morbid obesity contribute to the risk of chronic kidney disease.
African Americans experience higher rates of chronic kidney disease (CKD) than do whites. It was hypothesized that racial differences in modifiable factors would account for much of the excess risk of CKD. A cohort study of 9082 African-American and white adults of age 30 to 74 yr, who participated in the Second National Health and Nutrition Examination Survey in 1976 to 1980 and were monitored for vital status through 1992 in the Second National Health and Nutrition Examination Survey Mortality Study, was conducted. Incident CKD was defined as treated CKD cases (ascertained by linkage to the Medicare Registry) and deaths related to kidney disease. The incidence of all-cause CKD was 2.7 times higher among African Americans, compared with whites. Adjustment for sociodemographic factors decreased the relative risk (RR) to 2.49, explaining 12% of the excess risk of CKD among African Americans. Further adjustment for lifestyle factors explained 24% of the excess risk, whereas adjustment for clinical factors alone explained 32%. Simultaneous adjustment for sociodemographic, lifestyle, and clinical factors attenuated the RR to 1.95 (95% confidence interval, 1.05 to 3.63), explaining 44% of the excess risk. Although the excess risk of CKD among African Americans was much greater among middle-age adults (30 to 59 yr of age; RR = 4.23, statistically significant) than among older adults (60 to 74 yr of age; RR = 1.27), indicating an interaction between race and age, the same patterns of explanatory factors were observed for the two age groups. Nearly one-half of the excess risk of CKD among African-American adults can be explained on the basis of potentially modifiable risk factors; however, much of the excess risk remains unexplained.