Ongoing treatment with renin-angiotensin-aldosterone-blocking agents does not predict normoalbuminuric renal impairment in a general type 2 diabetes population ☆ Hanri Afghahi a , Mervete Miftaraj b , Ann-Marie Svensson b , Henrik Hadimeri a , Soffia Gudbjörnsdottir c , Björn Eliasson c , Maria K. Svensson d, ⁎ on behalf of the Swedish National Diabetes Register (NDR) a Department of Nephrology, Kärnsjukhuset, Skövde, Sweden b Center of Registers in Region Västra Götaland, Gothenburg, Sweden c Department of Medicine, University of Gothenburg, Göteborg, Sweden d Department of Nephrology, University of Gothenburg, Göteborg, Sweden abstract article info Article history: Received 2 July 2012 Received in revised form 12 September 2012 Accepted 17 October 2012 Available online 12 December 2012 Keywords: Normoalbuminuria Renal impairment Type 2 diabetes Renin-angiotensin-aldosterone system Cardiovascular Risk factors Aim: To examine the prevalence and the clinical characteristics associated with normoalbuminuric renal impairment (RI) in a general type 2 diabetes (T2D) population. Methods: We included 94 446 patients with T2D (56% men, age 68.3 ± 11.6 years, BMI 29.6 ± 5.3 kg/m 2 , diabetes duration 8.5 ± 7.1 years; means ± SD) with renal function (serum creatinine) reported to the Swedish National Diabetes Register (NDR) in 2009. RI was defined as estimated glomerular filtration (eGFR) b 60 ml/min/1.73 m 2 and albuminuria as a urinary albumin excretion rate (AER) N 20 μg/min. We linked the NDR to the Swedish Prescribed Drug Register, and the Swedish Cause of Death and the Hospital Discharge Register to evaluate ongoing medication and clinical outcomes. Results: 17% of the patients had RI, and 62% of these patients were normoalbuminuric. This group of patients had better metabolic control, lower BMI, lower systolic blood pressure and were more often women, non- smokers and more seldom had a history of cardiovascular disease as compared with patients with albuminuric RI. 28% of the patients with normoalbuminuric RI had no ongoing treatment with any RAAS- blocking agent. Retinopathy was most common in patients with RI and albuminuria (31%). Conclusions: The majority of patients with type 2 diabetes and RI were normoalbuminuric despite the fact that 25% of these patients had no ongoing treatment with RAAS-blocking agents. Thus, RI in many patients with type 2 diabetes is likely to be caused by other factors than diabetic microvascular disease and ongoing RAAS-blockade. © 2013 Elsevier Inc. All rights reserved. 1. Introduction The incidence and prevalence of type 2 diabetes (T2D) is increasing globally (Wild et al., 2004). Having diabetes increases the risk of developing end stage of renal disease (ESRD) 10–12 times (Brancati et al., 1997). Diabetic nephropathy (DN) is currently the main underlying primary disease for need of renal replacement therapies, i.e. dialysis and kidney transplantation, in many countries (Williams, 2010). Albuminuria is a well-known risk factor for development of DN and predicts progression to ESRD (de Zeeuw et al., 2004). In addition, both albuminuria and reduced renal function are independent predictors of cardiovascular disease (CVD), as well as cardiovascular and all-cause mortality (Sasso et al., 2012). Even though T2D is one of the leading causes of ESRD, not all patients with T2D develop renal dysfunction and ESRD during their lifetime (Adler et al., 2003). Recent studies have shown that albuminuria does not always precede development of renal impairment (RI) in T2D and other markers are therefore needed to monitor renal function (Ito et al., 2010; Kramer et al., 2007). Around 10–20% of all patients with T2D have normoalbuminuric RI (Penno et al., 2011; Rigalleau et al., 2007a; Yokoyama et al., 2009) and, in fact, the majority of patients with T2D and RI are normoalbuminuric (MacIsaac et al., 2004; Thomas et al., 2009). Concomitant retinopathy is often used as a clinical indicator of DN, but the association between retinopathy and nephropathy in T2D is relatively weak and only Journal of Diabetes and Its Complications 27 (2013) 229–234 Abbreviations: eGFR, estimated glomerular filtration rate; MDRD, Modified Diet in Renal Disease; C-G, Cockcroft-Gault; ESRD, end stage renal disease; T2D, type 2 diabetes; AER, albumin excretion rate; NDR, Swedish National Diabetes Register; CVD, cardiovascular disease; CHF, chronic heart failure; RAAS, renin-angiotensin aldosterone system. ☆ Conflict of interest statement: The results presented in this paper have not been published previously in whole or part. None of the authors have any conflict of interest to declare. ⁎ Corresponding author. Tel.: +46 761 301133; fax: +46 31 824660. E-mail address: maria.svensson@wlab.gu.se (M.K. Svensson). 1056-8727/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jdiacomp.2012.10.010 Contents lists available at SciVerse ScienceDirect Journal of Diabetes and Its Complications journal homepage: WWW.JDCJOURNAL.COM