First, the greater risk of osteoporosis and fracture with PPIs such as esomeprazole, omeprazole, pantoprazole, and rabeprazole has been shown in many studies, 2,3 although this effect may not be generalized to all PPIs. Moreover, the type of each PPI molecule may affect PTH levels differ- ently. PTH levels may not be attributable to a group effect of PPIs. It would be better if the authors could provide information about the individual effects of each PPI type on PTH levels. Second, the authors mention that the inclusion criteria included measurement of calcium, vitamin D, and PTH levels, but seeing as it is a retrospective study, there is no information about levels of these parameters before starting a PPI or bisphosphonates prescription. Therefore, the possi- bility cannot be excluded that the calcium levels of subjects in the PPI group were lower before the use of the medication. Fatih Sumer, MD Gozde Sengul Aycicek, MD Gunes Arik, MD Ozgur Kara, MD Busra Canbaz, MD Zekeriya Ulger, MD Division of Geriatrics, Faculty of Internal Medicine, Gazi University, Ankara, Turkey ACKNOWLEDGMENTS Conflict of Interest: The authors state that they have no conflicts of interest. Author Contributions: Sumer, Aycicek, Arik, Kara, Canbaz: preparation of manuscript. Ulger: review of concept. Sponsor’s Role: No sponsor. REFERENCES 1. Hinson AM, Wilkerson BM, Rothman-Fitts I et al. Hyperparathyroidism associated with long-term proton pump inhibitors independent of concurrent bisphosphonate therapy in elderly adults. J Am Geriatr Soc 2015;63:2070– 2073. 2. van der Hoorna MC, Tettc SE, de Vriesd OJ et al. The effect of dose and type of proton pump inhibitor use on risk of fractures and osteoporosis treatment in older Australian women: A prospective cohort study. Bone 2015;81:675–682. 3. Adams AL, Black MH, Zhang JL et al. Proton-pump inhibitor use and hip fractures in men: A population-based case–control study. Ann Epidemiol 2014;24:286–290. RESPONSE TO SUMER AND COLLEAGUES To the Editor: We thank Sumer and colleagues 1 for their interest in our research. 2 We agree that different types of proton pump inhibitors (PPIs) may affect parathyroid hor- mone (PTH) levels differently. Future studies may also find that PTH levels vary according to different PPI dosing, drug formulation (immediate vs delayed release), and routes of administration (oral, intravenous, gastrostomy tube). Our study also assumed a group effect for bisphos- phonates (alendronate, ibandronate, zoledronate, rise- dronate). Thus, one could alternatively ask, “Can we equate all bisphosphonates with each other?” In summary, although we agree that greater efforts are needed to answer these important questions in the context of PTH levels and bone health, our study design and population size were not sufficient to speculate on such matters. Sumer and colleagues correctly highlight that the possi- bility cannot be excluded that calcium levels of subjects in the PPI group were already lower before starting PPIs. We agree and indirectly address this point in the Discussion sec- tion (in the context of higher PTH levels rather than lower calcium levels): “The present study was unable to differenti- ate whether PPIs (directly or indirectly) increase PTH or, alternatively, whether high PTH increases the likelihood of PPI exposure. Indigestion and other gastrointestinal com- plaints are classic symptoms and signs associated with hyperparathyroidism (abdominal groans). It should not be surprising then that people with higher PTH commonly require medications that treat PTH-associated symptoms.” 2 There is also evidence that PPIs play a more-physiological and -immediate role in lowering calcium and increasing PTH. 3,4 These roles were considered in more depth in the Discussion section. 2 In any case, we agree that prospective studies are now needed to determine whether our findings are of any clinical utility with regard to PPI-induced bone fragility or can be attributed to confounding comorbidities more common in individuals chronically exposed to PPIs. Andrew M. Hinson, MD Brendan C. Stack, Jr, MD Department of Otolaryngology—Head and Neck Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas Donald L. Bodenner, MD, PhD Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas ACKNOWLEDGMENTS Conflict of Interest: The authors declare no competing interests. Author Contributions: Hinson: first author, prepara- tion of manuscript, analysis and interpretation of data, drafting of reply. Bodenner: senior author, study concept and design, acquisition of subjects and data, analysis and interpretation of data, final approval of manuscript and reply. Sponsor’s Role: None. REFERENCES 1. Sumer F, Sengul AG, Gunes A et al. Can we equate all proton pump inhibi- tors with one another? J Am Geriatr Soc 2016;64:1150–1151. 2. Hinson AM, Wilkerson BM, Rothman-Fitts I et al. Hyperparathyroidism associated with long-term proton pump inhibitors independent of concurrent bisphosphonate therapy in elderly adults. J Am Geriatr Soc 2015;63:2070– 2073. 3. Moayyedi P, Leontiadis GI. The risks of PPI therapy. Nat Rev Gastroenterol Hepatol 2012;9:132–139. 4. Mizunashi K, Furukawa Y, Katano K et al. Effect of omeprazole, an inhibi- tor of H+, K(+)-ATPase, on bone resorption in humans. Calcif Tissue Int 1993;53:21–25. 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