Dear Editor,

We recently read with great interest the article written by Pasina et al. with the title “Orthostatic hypotension among elderly patients in Italian internal medicine wards: an observational study”, published in a past issue of “Internal and Emergency Medicine” [1]. Orthostatic hypotension affects 20% of the elderly population and it is associated with 35% increased risk in all caused mortality [2, 3]. Although orthostatic hypotension is commonly seen and associated with poor outcomes, it can be overlooked in medical wards. So, the paper is worthy because it draws attention to high prevalence and importance of the orthostatic hypotension.

Although many causes of orthostatic hypotension were evaluated in the study, hemoglobin levels or anemia status of the patients were not discussed. Anemia is a common problem and it is associated with 80% increased mortality rate in hospitalized elderly patients [4]. Anemia may also cause or exacerbate the orthostatic hypotension and it is recommended to be evaluated in case of orthostatic hypotension. Anemia causes reduced systemic vascular resistance, which can result in orthostatic hypotension, by inducing nitric oxide synthesis and decreasing blood viscosity. On the other hand, the authors found that renal failure was a risk factor for persistent orthostatic hypotension in the study. Anemia is also very common in chronic renal failure patients and its incidence increases as glomerular filtration rate decreases. Liu et al. showed that reduced hemoglobin level causes impaired orthostatic blood pressure stabilization in renal failure and reduced hemoglobin can be one of main contributors to orthostatic hypotension in patients with renal failure [5]. Anemia is not only associated with orthostatic hypotension and renal failure, but anemia is also associated with poor outcomes such as frailty, increased hospitalizations rates and increased mortality rates in elderly [4]. To sum up, anemia can be associated with orthostatic hypotension, renal failure and mortality which were evaluated in the study. Anemia and related factors may be examined in another analysis in the cohort of this comprehensive article can be fruitful.