Editorial comment to: Impact of Sexual Activity on Gly- cated Hemoglo bin Levels in Patients with Type 2 Diabetes Mellitus after Penile Prosthesis Implantation Mohammad Reza Safarinejad, MD Clinical Center for Urological Disease Diagnosis and Private Clinic Specialized in Urologi- cal and Andrological Genet- ics,Tehran, Iran. E-mail: info@safarinejad.com The authors have addressed an important issue. Congratulation! Type 2 diabetes mellitus (DM) is a complex and multifactor metabolic disorder. One of the complications of type 2 DM is the sexual dysfunction, mainly in the form of erectile dysfunction in men. Hemoglobin A 1C (HbA 1c ) is an in- valuable tool for watching long-term glycemic control in patients with DM. In present retrospective study the authors aimed to determine the relationship between sexual activity and serum levels of HbA 1c with an inappropriate manner. As a result, the manuscript suffers from some important drawbacks. There are many confounding factors which can interfere with serum HbA 1c concentration measurements. Also, there are sev- eral situations in which the level of HbA 1c may not loyally reflect the actual values. Without adjusting for these confounding factors, the results might not be reliable. Genetic variants (e.g. HbS trait, HbC trait), elevated fetal hemoglobin (HbF) and chemically altered de- rivatives of hemoglobin (e.g. carbamylated Hb) all can affect the accuracy of serum HbA 1c measurements. The impacts differ depending on the specific Hb variant or derivative and the method used for serum HbA 1c measurement. Any disorder or illness that reduces erythrocyte survival or shortens mean erythrocyte age will falsely lower serum HbA 1c test results irrespective of the laboratory method used.(1) HbA 1c results from pa- tients with HbSS, HbCC, and HbSC must be interpreted with cautiousness given the pathological processes, including anemia, increased red blood cell turnover, and transfusion, that adversely affect serum HbA 1c levels. Other methods of measurement such as glycated serum protein or glycated albumin would be considered for these cases. There are some systemic disorders such as certain forms of dyslipidemia, malignancies, and cirrhosis which can affect the serum HbA 1c concentrations. The iron deficiency anemia is a common condition which can lead to an increase in serum HbA 1c level by 1% to 1.5%.(2) In agreement with that observation, iron replacement therapy decreases both serum HbA 1c and fructosamine levels in individuals with or without DM.(3) Also, any medical disorders or illnesses which are associated with changes in the relationship between mean glycemia and serum HbA 1c concentration, can alter serum HbA 1c levels too. The main disorders are those affecting red blood cells, comprising persistent fetal hemoglobin, hemoglobin S, C, or D, end stage renal dis- ease, or diseases characterized by hemolysis or other conditions with decreased life span of red blood cells.(4) 1817 Sexual Dysfunction and Fertility UROLOGY JOURNAL Vol. 11 No. 04 July - August 2014 1818 abetes Registry. Diabetes Care. 2013;36:611-7. 6. Pani LN, Korenda L, Meigs JB, et al. Effect of aging on A1C levels in individuals without diabetes: evidence from the Framingham Offspring Study and the National Health and Nutrition Examination Survey 2001- 2004. Diabetes Care. 2008;31:1991-6. 7. Harding AH, Sargeant LA, Welch A, Oakes S, et al. Fat consumption and HbA(1c) levels: the EPIC-Norfolk study. Diabetes Care. 2001;24:1911- 6. The HbA 1c concentrations also have a quadratic association with sleep duration; namely, a shorter or longer sleep duration is associated with a higher level compared with a sleep duration of 6.5-7.4 h.(5) Some of the factors that influence HbA1c and its measurement are as below:(1-4) Increased HbA 1c : iron deficiency, vitamin B12 deficiency, decreased erythropoiesis, alcoholism, chronic renal failure, splenectomy, hy- perbilirubinemia, carbamylated hemoglobin, large doses of aspirin, chronic opiate use, genetic heterozygous variants of hemoglobins S, C and E, medications, such as corticosteroids and antipsychotic agents, malaria, rheumatoid arthritis and increased serum triglyceride. Decreased HbA 1c : administration of erythropoietin, iron and vitamin B12, reticulocytosis, chronic liver disease, small doses of aspirin, vi- tamin C and E, certain hemoglobinopathies, splenomegaly, medica- tions such as antiretrovirals, ribavirin and dapsone, acute and chronic blood loss, hemolytic anemia, hereditary persistence of hemoglobin F, genetic heterozygous variants of hemoglobins S, C and E and mal- nutrition. It has been demonstrated that older non-diabetic individuals have higher HbA 1c values than younger subjects, being approximately 0.4% higher at 70 years than at 40 years,(6) even after adjusting for confounding factors. Lower total fat intake is associated with lower HbA 1c . Saturated fat intake is positively associated with HbA 1c .(7) Fi- nally, measurement method of HbA 1c is fundamental. Accurate and reliable methods to measure HbA 1c are necessary for optimal use. The most widely adopted system is that of the National Glycohemoglobin Standardization Program (NGSP). None of the above mentioned confounding factors have been ad- dressed in this study. Accounting for all of them is nearly impossi- ble. But, it was very worthwhile if the study results have been put in multivariate regression analysis and adjusted for total energy intake, protein, alcohol use, age, family history of diabetes and physical ac- tivity. Therefore, I believe that the results of the present study should be interpreted with caution. REFERENCES 1. Goldstein DE, Little RR, Lorenz RA, Malone JI, Nathan D, Peterson CM. American Diabetes Association Technical Review on Tests of Gly- cemia. Diabetes Care. 1995;18:896-909. 2. Sundaram RC, Selvaraj N, Vijayan G, Bobby Z, Hamide A, Rattina Das- se N. Increased plasma malondialdehyde and fructosamine in iron defi- ciency anemia: effect of treatment. Biomed Pharmacother. 2007;61:682- 5. 3. Coban E, Ozdogan M, Timuragaoglu A. Effect of iron deficiency ane- mia on the levels of hemoglobin A1c in nondiabetic patients. Acta Hae matol. 2004;112:126-8. 4. Peacock TP, Shihabi ZK, Bleyer AJ et al. Comparison of glycated albu min and hemoglobin A(1c) levels in diabetic subjects on hemodialysis. Kidney Int. 2008;73:1062-8. 5. Ohkuma T, Fujii H, Iwase M, et al. Impact of sleep duration on obesity and the glycemic level in patients with type 2 diabetes: the Fukuoka Di Impact of Sexual Activity on HbA 1c Levels-Talib et al Reply by Author As principal co-authors of this paper, we welcome the opportunity to respond to the editorial comments on our article. In editorial comment, it was mentioned that there are some genetic variants, systemic illnesses and disorders, which can affect the serum Hemoglobin A 1C (HbA 1c ) concentrations. Our study was performed retrospectively and analyzed medical records from computer files of patients that underwent penile prosthesis implantation. We strongly agree with the comment and accept that serum HbA 1c concentrations could be effected by some situations. However, HbA 1c is the most commonly used test to examine long-term glycemic control in patients with diabetes mellitus. We also agree that adjusted results after getting information on diet and physical activity would make our study more powerful. As we pointed out in discussion section of our study, observational nature of our cohort, our findings must be interpreted within the context of the limitations applicable to observational, retrospective data. As mentioned in the editorial comment, it has been demonstrated that older non-diabetic individuals have higher HbA 1c values than younger subjects. In our study, we compared the HbA 1c results nearly 2 years (the mean time was 22.6 months) after the surgery of the same patients. We believe that this time period is insignificant and valid for every patients included in this study. 1819 Sexual Dysfunction and Fertility