Nonalcoholic Fatty Liver Disease A Risk Factor for Microalbuminuria in Type 2 Diabetic Patients

Nonalcoholic Fatty Liver Disease A Risk Factor for Microalbuminuria in Type 2 Diabetic Patients F. CASOINIC 1, D. SÂMPELEAN 1, CĂTĂLINA BĂDĂU 2, LUCHIANA PRUNĂ 3 1 University of Medicine and Pharmacy Cluj-Napoca, IVth Medical Clinic, Department of Diabetology 2 Heart Institute Niculae Stancioiu, Cluj-Napoca 3 County Hospital Baia Mare, Department of Diabetology The aim of our study was to assess the presence of microalbuminuria in diabetic subjects with nonalcoholic fatty liver disease () compared with diabetic patients and to correlate this with inflammatory markers such as high sensitive C- reactive protein (hscrp). Material and Methods. The study was conducted on 75 diabetic subjects with ultrasonographical, in which alcohol consumption and other causes of chronic liver disease have been excluded. The exclusion criteria also included smoking, arterial hypertension, known renal disease. The control group consisted of 70 diabetic patients, matched for age and gender, ultrasonographical evidence of. In all subjects we measured height, weight, BMI, fasting glucose, HbA1c, total cholesterol, LDL and HDLcholesterol, triglycerides, serum transaminases, hsc-reactive protein and microalbuminuria. A p-value<0.05 was considered statistically significant. Results. Microalbuminuria was significantly more frequent in subjects with than in controls (12.7% vs 7.8%, p<0.05). Microalbuminuria was positively correlated with hscrp levels. In conclusion is positively correlated with microalbuminuria-marker of early stage CKD, in diabetic patients. This seems to be related to higher levels of proinflammatory factors released by the liver, such as hscrp. Key words: nonalcoholic fatty liver disease, microalbuminuria, cardiometabolic risk, diabetes mellitus. Nonalcoholic fatty liver disease (), the hepatic manifestation of the metabolic syndrome [1 3], is associated with obesity, prediabetes, type 2 diabetes mellitus, dyslipidaemia, insulinresistance and arterial hypertension [2][3]. In type 2 diabetic patients studies have shown that is correlated with an increase in total cardiovascular risk independently of the other components of the metabolic syndrome [4 7]. Moreover, the presence of endothelial dysfunction in patients with has been demonstrated using the flow mediated vasodilatation method [8]. Microalbuminuria as an indicator of endothelial dysfunction is at present the best documented predictor for the development of diabetic chronic renal disease. Genetic susceptibility, metabolic abnormalities, hemodynamic changes, upregulated growth factors and cytokines may play a part in the development of diabetic micro-albuminuria [9]. The pathogenetic link between in diabetic patient and microalbuminuria is supposed to be represented by proinflammatory cytokines secreted by the liver [10]. The presence of microalbuminuria in diabetic patients with may increase the prediction of cardiovascular risk and that of chronic kidney disease, with concurrent important therapeutical management implications. It is thus possible to identify a subgroup of diabetic patients who require a more intensive treatment to reduce the risk of future cardiovascular events and chronic kidney disease [10]. The aim of our study was to determine the prevalence of microalbuminuria and to correlate it with chronic inflammation markers such as high sensitive C reactive protein (hcrp) in diabetic patients with versus diabetic patients. MATERIAL AND METHODS SUBJECTS The study was conducted on 75 diabetic patients with ultrasonographically diagnosed. The ROM. J. INTERN. MED., 2009, 47, 1, 55 59

56 F. Casoinic et al. 2 control group included 70 diabetic patients ultrasonographical evidence of, matched for age, gender and the time from diagnosis of diabetes. In both groups the exclusion criteria were: alcohol consumption, smoking, infection with hepatitic viruses B and C, more rare causes of chronic hepatopathy (autoimmune hepatitis, hemochromatosis), known renal disease, urinary infection, arterial hypertension and severely unbalanced diabetes mellitus. CLINICAL MEASUREMENTS AND LABORATORY PROCEDURES Both groups were evaluated both clinically and paraclinically. Information regarding smoking, alcohol intake and current used medication were obtained by questionnaire. Body mass index was measured dividing weight in kilograms by height squared meters. Abdominal circumference was measured at the level of the umbilicus. Blood pressure was measured repeatedly using a mercury sfigmanometer. Biochemical parameters were determined using morning drawn venous blood, after an overnight fast. We have determined serum transaminases, gamma glutamyltransferase (with reference range of 10 35 IU/L for ASAT, 10 40 IU/L ALAT, γgt), fasting glucose, HbA1c, total cholesterol, HDL cholesterol, hscrp (reference range <=3 mg/dll, serum creatinine. Albumin excretion rate was measured from an early morning urine sample as the albumin/ creatinine ratio (ACR). Microalbuminuria was defined as albumin excretion rate of 30 to 299 g/mg creatinine. Hepatic ultrasonography was performed by a single examiner blinded to patient clinical status. Ultrasonographical criteria for hepatic steatosis were diffuse echogenicity of liver relative to kidney and posterior attenuation of ultrasound beam [11]. Statistical analysis was performed using SPSS 11.0. The data are expressed in means ± SD. Unpaired t test for numerical variables and X2 test for categorical variables were used. A p value <0.05 was considered statistically significant. RESULTS The characteristics of patients are shown in Table I. Diabetic patients with NFLD were more likely to be men, older than controls, with a tendency towards obesity and a longer duration of diabetes. Table I Clinical and biochemical characteristics of the groups studied Variables Diabetes mellitus P value with N 75 70 Sex (%males) 65.3 52.2 >0.05 Age (years) 63 ± 5 59 ± 3 >0.05 BMI (kg/m 2 ) 29.4 ± 2 27.1 ± 4 <0.05 Diabetes duration (years) 9 ± 2 7 ± 3 <0.05 Systolic blood pressure (mmhg) 133 ± 5 130 ± 3 >0.05 Diastolic blood pressure (mmhg) 85 ± 5 80 ± 4 >0.05 HbA1c 7.4 ± 1.0 6.8 ± 0.7 <0.05 Triglycerides (mmol/l) 1.51 ± 0.5 1.42 ± 0.4 <0.05 HDL cholesterol (mmol/l) 1.38 ± 0.4 1.42 ± 0.3 <0.05 LDL cholesterol (mmol/l) 3.35 ± 0.5 3.33 ± 0.4 >0.05 ASAT (IU/L) 29 ± 10 22 ± 4 <0.05 ALAT (IU/L) 30 ± 9 23 ± 3 <0.05 γgt (UI/L) 28 ± 10 21 ± 5 <0.05 Creatinine (mg/dl) 0.91 ± 0.1 0.87 ± 0.2 >0.05 Metabolic syndrome (IDF criteria 2005)(%) 88 72 <0.05 Biologically the diabetics with had a poorer long term glycemic control, reflected by a significantly higher value of HbA1c than controls (7.4% vs 6.8%). The presence of was also

3 Nonalcoholic fatty liver disease 57 associated with a more deleterious lipidic profile, with a tendency towards higher triglycerides and low HDL cholesterol levels, compared with controls. Regarding liver enzymes, diabetic patients with had higher levels of both transaminases and γgt, thus reflecting the presence in this group of patients with steatohepatitis. The prevalence of microalbuminuria was significanty higher in diabetic patients with, as shown in Fig. 1 (12 % versus 7.14%). 14 12 10 8 6 4 2 0 16 14 12 10 8 6 4 2 0 12 % with 12% 8.57 % p <0,01 7.14 % Fig. 1. The prevalence of microalbuminuria in diabetic patients with versus controls. Using the elevated levels of serum transaminases as surrogate marker of hepatic injury, we subsequently divided the diabetic patients with into two subgroups: simple steatosis (with normal levels of transaminases) and respectively steatohepatitis (with elevated serum transaminases). Comparing these two subgroups we found that patients with steatohepatitis had a higher prevalence of microalbuminuria than those with simple steatosis (Fig. 2). Simple stetosis Steatohepatitis 15 % 7.14 % Controls Fig. 2. Prevalence of microalbuminuria in the two subgroups. High sensitive C reactive protein levels were significantly higher in diabetic patients with compared to controls, and were correlated with the presence of microalbuminuria, as shown in Fig. 3. 8 7 6 5 4 3 2 1 0 5.9 with 7.2 with with 5.5 4.9 5.3 with 4.5 Fig. 3. Mean values of hscrp in the diabetic patients with and microalbuminuria, versus non with or microalbuminuria. DISCUSSION In this study we have found that the presence of in diabetic patients was associated with a higher prevalence of microalbuminuria and positively correlated with hscrp levels. Our findings support the results reported by Targher et al., that suggested that the presence of in diabetic patients increases the risk of microvascular complications, such as nephropaty and retinopathy [10]. Microalbuminuria is at present the best noninvasive independent predictor for endothelial dysfunction and also for cardiovascular morbidity and mortality. In our study the association between and microalbuminuria in diabetic patients was independent of arterial hypertension. The mechanism by which could contribute to endothelial dysfunction is poorly understood. Our data suggest that promotes inflammation, probably by releasing proinflammatory cytokines from injured hepatocytes, due to reactive oxygen species derived from steatosis stimulated fatty liver oxidation. A pathogenetic circle is thus promoted enhancing consequently both hepatic injury and subclinical systemic inflammation. In our study diabetic patients with elevated serum transaminases had the highest prevalence of microalbuminuria and the highest hscrp levels. Further studies are needed to establish the exact mechanism by which the deleterious effects of are exercised.

58 F. Casoinic et al. 4 In view of the emerging evidence that is an independent cardiovascular risk factor (4 7), our data support the conviction that diabetic patients with require a more attentive assessment of total cardiovascular risk and thus a more aggressive approach in order to diminish the number of future cardiovascular events. The main limitation of our study is that the diagnosis of was not performed by liver biopsy, and was based instead on clinical and ultrasonographical data. Liver biopsy is not easily applied in epidemiological studies. Ultrasonography has a good sensitivity and specificity for moderate and severe steatosis, but a lower sensitivity for hepatic fat infiltration under 33% [11]. This tends to underestimate the cases of. In conclusion in diabetic patients increases the risk for microalbuminuria and thus for future cardiovascular events and chronic kidney disease. Scopul studiului de faţă constă din evaluarea prezenţei microalbuminuriei la pacienţii diabetici cu FGNA comparativ cu cei fără FGNA şi corelarea acesteia cu markeri ai inflamaţiei cum este proteina C reactivă cu sensibilitate înaltă. Material şi metodă. Studiul a fost desfăşurat pe un grup de 75 de pacienţi diabetici cu FGNA diagnosticat ultrasonografic, la care s-au exclus consumul de alcool precum şi alte cauze de boală cronică hepatică, fumatul, hipertensiunea arterială şi boala renală preexistentă. Grupul de control a fost constituit din 70 de pacienţi diabetici, fără dovezi ecografice de FGNA. La toţi pacienţii s-au determinat parametrii antropometrici, glicemia à jeun, HbA1c, colesterolul total, LDL şi HDL colesterolul, trigliceridele, transaminazele serice, hs PCR şi microalbuminuria. Analiza statistică a fost efectuată cu SPSS11.0. O valoare a p<0,05 a fost considerată semnificativ statistică. Rezultate. Microalbuminuria a fost semnificativ mai frecventă la subiecţii cu FGNA decât la grupul de control (12,7% vs 7,8%, p<0,05). Microalbuminuria s-a corelat pozitiv cu hscrp la pacienţii diabetici cu FGNA. In concluzie FGNA la pacienţii diabetici, rezervorul cel mai mare de factori de risc din patologie se corelează cu prezenţa microalbuminuriei-marker de boală cronică renală încă din stadiu precoce. Nivelele plasmatice crescute de hscrp precum şi alte cytokine proinflamatorii eliberate de ficat par să joace un rol patogenetic în acest sens. Corresponding author: F. Casoinic, MD IVth Medical Clinic, CF University Hospital, Cluj-Napoca 18, Republicii St., 400015 Cluj-Napoca, Romania E-mail: fcassoinic@yahoo.com REFERENCES 1. McCULLOUGH AJ., The clinical features, diagnosis and natural history of nonalcoholic fatty liver disease. Clin Liver Dis., 2004, 8:521 533. 2. MARCHESINI G., BUGIANESI E., FORLANI G., CERRELI F., LENZI M., Nonalcoholic fatty liver disease, steatohepatitis and the metabolic syndrome. Hepatology, 2003, 37:917 923. 3. ANGULO P., Nonalcoholic fatty liver disease. N. Engl. J. Med., 2002, 346:1221 1231. 4. TARGHER G., BERTOLINI L., POLI F., RODELLA S., SCALA L. et al., Nonalcoholic fatty liver disease and risk of future cardiovascular events among type 2 diabetic patients. Diabetes, 2005, 54:3541 3546. 5. TARGHER G., BERTOLINI L., PADOVANI R. et al., Prevalence of nonalcoholic fatty liver disease and its association with cardiovascular disease among type 2 diabetic patients. Diabetes Care, 2007, 27:1212 1218. 6. TARGHER G., BERTOLINI L., PADOVANI R., RODELLA S., ZOPPINI G, Relations between carotid artery wall thickness and liver histology in subjects with nonalcoholic fatty liver disease. Diabetes Care, 2006, 29:1325 1330.

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