associated with loop diuretic use and that the rise in serum PTH level was a compensatory response to maintain serum calcium within the normal range. This relationship has been seen in specific patient populations, including those with chronic kidney disease2 or congestive heart failure.3 Thus, in selecting covariates we included both estimated glomerular filtration rate and a history of congestive heart failure in our final model. Loop diuretics are occasionally used in the treatment of other conditions, such as resistant hypertension. Some patients with resistant hypertension who are prescribed loop diuretics may have a component of chronic kidney disease, which may also influence the relationship with PTH.4 To address the suggestion by García de Tena et al, we revisited the National Health and Nutrition Examination Survey (NHANES) data set: a questionnaire item captured a history of high blood pressure, and the examination portion of NHANES included up to 3 blood pressure measurements (in our cohort, 75% of patients had 3 blood pressure measurements). We added both assessments of hypertension to our previously published model, defining measured hypertension as a mean blood pressure higher than 140/90 mm Hg. Regardless of which definition was applied (questionnaire-based definition or measured blood pressure), loop diuretic use remained a significant predictor of PTH (β = 0.11 [P = .001] and β = 0.12 [P < .001], respectively). We thank García de Tena and colleagues for their thoughtful suggestion. There may well be confounding between loop use and a diagnosis of hypertension; however, this did not extinguish the significant relationship between loop diuretic use and PTH level.
Conflict of Interest Disclosures: None reported. 1. Corapi KM, McMahon GM, Wenger JB, Seifter JL, Bhan I. Association of loop diuretic use with higher parathyroid hormone levels in patients with normal renal function. JAMA Intern Med. 2015;175(1):137-138. 2. Isakova T, Anderson CA, Leonard MB, et al; Chronic Renal Insufficiency Cohort (CRIC) Study Group. Diuretics, calciuria and secondary hyperparathyroidism in the Chronic Renal Insufficiency Cohort. Nephrol Dial Transplant. 2011;26(4):1258-1265. 3. Hagström E, Ingelsson E, Sundström J, et al. Plasma parathyroid hormone and risk of congestive heart failure in the community. Eur J Heart Fail. 2010;12 (11):1186-1192. 4. Levin A, Bakris GL, Molitch M, et al. Prevalence of abnormal serum vitamin D, PTH, calcium, and phosphorus in patients with chronic kidney disease: results of the study to evaluate early kidney disease. Kidney Int. 2007;71(1):31-38.
CORRECTION Incorrect MACE End Point: In the article titled “Association of β-Blocker Therapy With Risks of Adverse Cardiovascular Events and Deaths in Patients With Ischemic Heart Disease Undergoing Noncardiac Surgery: A Danish Nationwide Cohort Study,” published online November 18, 2013, and also in the March 2014 issue of JAMA Internal Medicine (2014;174:336-344. doi:10.1001/jamainternmed.2013 .11349), an error ocurred in one part of the composite major cardiovascular adverse events (MACE) end point. All analyses were recalculated after correction of the end point, and the values were substantially unaltered. More important, none of the study’s conclusions were affected. This article was corrected online.
Author Affiliations: Division of Nephrology, Massachusetts General Hospital, Boston.
Missing Signature Block for In Reply Letter: The “In reply” letter to “Lactulose vs Polyethylene Glycol for Treatment of Hepatic Encephalopathy” in the May issue of JAMA Internal Medicine (2015;175:868-869) was missing the signature block. The signature block text should read as follows: Robert S. Rahimi, MD, MS; Jennifer A. Cuthbert, MD; Don C. Rockey, MD; Author Affiliations: Annette C. and Harold C. Simmons Transplant Institute, Baylor University Medical Center, Dallas, Texas (Rahimi); Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas (Cuthbert); Parkland Memorial Hospital, Parkland Health and Hospital System, Dallas, Texas (Cuthbert); Department of Internal Medicine, Medical University of South Carolina, Charleston, South Carolina (Rockey).
JAMA Internal Medicine June 2015 Volume 175, Number 6 (Reprinted)
Kristin M. Corapi, MD, MMSc Julia B. Wenger, MPH Ishir Bhan, MD, MPH
Corresponding Author: Kristin M. Corapi, MD, MMSc, Division of Nephrology, Massachusetts General Hospital, 165 Cambridge St, Ste 302, Boston, MA 02114 ([email protected]
Copyright 2015 American Medical Association. All rights reserved.
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