Microvascular complications of type 2 diabetes mellitus ORIGINAL ARTICLE Corrected fructosamine, corrected glycated albumin and glycated β-lipoprotein/ β-lipoprotein ratio in patients with microvascular complications of type 2 diabetes mellitus Tejaskumar R. Kalaria1*, Vijay Vaidya2, Roma Shah3, Habibunnisha B. Sirajwala4 1MD MRCP (UK), Consultant diabetologist, Schvijk Hospital and Research Centre, Vadodara,2MD, Associate Professor, Department of Radiology, GMERS Medical College & Hospital, Gotri, Vadodara, 3MD, Consultant Anaesthesiologist, Freelancer, Vadodara, 4MD, Associate Professor, Department of Biochemistry, Government Medical College, Vadodara. ABSTRACT BACKGROUND AND OBJECTIVES: It has been shown in studies that there are significant variations in glycation of various serum proteins in type 2 diabetes mellitus patients with and without microvascular complications. Present study aimed to evaluate whether correcting serum fructosamine for serum total protein level, serum glycated albumin for serum albumin level and deriving ratio of glycated β-lipoprotein to total β- lipoprotein enhances their significance and correlation over and above serum fructosamine, glycated albumin and glycated β-lipoprotein respectively in type 2 diabetes mellitus patients with and without microvascular complications. METHODS: This was a cross sectional study involving 150 individuals at a tertiary care hospital in western India. 50 participants were healthy controls (group 1), 50 were type 2 diabetes patients without any evident microvascular complication (group 2) and 50 were type 2 diabetes patients with one or more microvascular complications (group 3). Serum fructosamine, FBS, PP2BS and other biochemical parameters were measured. Glycated albumin and glycated β-lipoprotein were measured by agarose gel electrophoresis followed by NBT staining. Corrected serum fructosamine, corrected glycated albumin and glycated β-lipoprotein/ β-lipoprotein ratio were calculated. Unpaired t-test was used to find out significance of difference between two groups and correlation coefficient to find out statistical correlation between two variables. RESULTS: Differences between the groups for corrected fructosamine, corrected glycated albumin and glycated β-lipoprotein/ β-lipoprotein ratio were significant (p<0.001). Corrected glycated albumin and corrected fructosamine correlated with FBS, PP2BS and with each other in all diabetic patients (groups 2 and 3). Glycated β-lipoprotein/ β-lipoprotein ratio was remarkably elevated in group 3 and it did not correlate either with corrected fructosamine or corrected glycated albumin. CONCLUSION: Glycated β-lipoprotein/ β- lipoprotein ratio was markedly elevated in type 2 diabetes patients with microvascular compilations but neither of corrected fructosamine, corrected glycated albumin or glycated β-lipoprotein/ β-lipoprotein ratio provided any information in addition to that provided by the uncorrected parameters. Key-words: Type 2 diabetes mellitus, microvascular complications, corrected fructosamine, corrected glycated albumin, corrected glycated β-lipoprotein INTRODUCTION serum proteins can also be used in similar Glucose molecules are joined to protein manner depending on their half-lives, most molecules through non-enzymatic widely evaluated of them is glycated glycation to form fructosamine and it albumin which is an indicator of reflects glycaemic control attained by glycaemic status over preceding 2-3 diabetic patient over previous 2 to 3 weeks weeks. Due to 3-5 day circulating half-life and is useful in monitoring the of LDL, glycated LDL level reflects mean effectiveness of therapy in diabetes, in a glycemia over the preceding week2. But, manner analogous to the determination of as serum total protein and serum albumin glycated hemoglobin1. Other glycated level tend to change widely in many conditions including diabetic nephropathy, *Corresponding Author: corrected serum fructosamine and glycated Dr. Tejaskumar R. Kalaria albumin might be more useful than the A/20, Sundarvan Society, uncorrected parameters3. Similarly as the New Sama Road, P.O., value of LDL varies widely from person to Chhani Road, Vadodara-390024, person, biologically as well as due to Contact No: +91 9998968153 treatment, the ratio of glycated β- E-mail address: [email protected] lipoprotein to total β-lipoprotein might 139 Int J Res Med. 2016; 5(3); 139-145 e ISSN:2320-2742 p ISSN: 2320-2734 Microvascular complications of type 2 diabetes mellitus provide additional information as outpatient department were enrolled in compared to glycated β-lipoprotein alone. groups 2 and 3 unless they met any of the The study was undertaken to assess levels exclusion criterions. Patients with type 1 of serum fructosamine corrected for serum diabetes mellitus, pregnant females and total protein, serum glycated albumin patients with diseases unrelated to diabetes corrected for serum albumin level and which might significantly alter serum glycated β-lipoprotein to total β- protein profile e.g. hepatic diseases, lipoprotein ratio in type 2 diabetes mellitus hematological malignancy, chronic patients with and without microvascular infections and inflammations like complications and to find out their tuberculosis, sarcoidosis, rheumatological correlation with the complications over diseases, infectious mononucleosis, AIDS and above the uncorrected parameters. were excluded from the study. Objectives MATERIAL AND METHODS of the study were explained to all subjects This was a hospital based cross-sectional eligible for this study. Informed written study consisting of three groups and total consent of all the subjects was obtained for 150 participants. Group 1 (control group, voluntary participation in study group, n=50) consisted of randomly selected age sample collection and for data utilisation and sex matched non-diabetic subjects. for the purpose of publication. Data were They were free from any ailment which recorded in a questionnaire designed for could affect the parameters under study the study and it included socio- (no clinical history or investigative result demographic data, presenting complains, showing involvement of any organ detailed diabetes history including system). They were selected from medical treatment and complications, history of and paramedical staff, attendants of other ailments, past, personal and family patients and persons coming to hospital for histories as well as findings of a thorough fitness purpose. Group 2 (type 2 diabetes physical examination. For each subject, mellitus patients without any overnight fasting blood sample was microvascular complications, n=50) collected in a fluoride vacutainer for FBS consisted of those with duration of and in a plain vacutainer for other diabetes 3 years or more, on life style biochemical parameters. Urine sample was modifications and oral anti-diabetic drugs collected in universal container for urine and free from clinical or laboratory creatinine and urine protein estimation. evidence of any microvascular Post prandial (2 hour) sample was complication of diabetes mellitus. Group 3 collected in a fluoride vacutainer for (type 2 diabetes mellitus patients with PP2BS estimation. Serum and plasma microvascular complications, n=50) were separated within an hour of consisted of those with duration of collection and stored at 2 to 8°C diabetes 3 years or more, on life style temperature till analyses were performed. modifications, oral anti-diabetic drugs, Electrophoresis was performed within 5 insulin or combination of all three and days whereas all the other parameters were diagnosed as having one or more estimated on the same day. FBS and microvascular complication of diabetes PP2BS were estimated by Glucose mellitus; either diabetic neuropathy Oxidase-Peroxidase (GOD-POD) (peripheral neuropathy diagnosed by 10 enzymatic end point method. Serum gm monofilament and reduced vibration fructosamine was estimated by NBT perception using 128 Hz tuning fork), colorimetric kinetic assay. Serum diabetic nephropathy (urine albumin ≥30 Creatinine concentration was measured by µg/ mg of creatinine with normal urine modified Jaffe’s kinetic method. Serum microscopy and not a known case of any total cholesterol was estimated by other kidney disease) or diabetic Cholesterol Oxidase-Peroxidase (CHOD- retinopathy (diagnosed by direct PAP) enzymatic end point method. Serum ophthalmoscopy after mydriasis). LDL cholesterol was measured by direct Consecutive patients attending the medical enzymatic method. Urinary creatinine was 140 Int J Res Med. 2016; 5(3); 139-145 e ISSN:2320-2742 p ISSN: 2320-2734 Microvascular complications of type 2 diabetes mellitus estimated by modified Jaffe’s kinetic Corrected serum fructosamine (µmol/gm method, urinary protein was measured by of total protein) was calculated by dividing Pyrogallol red end point method and serum fructosamine value (µmol/l) by urinary protein/creatinine ratio was serum total protein (gm/l). Corrected calculated. All biochemical investigations glycated albumin (µmol/gm of serum were performed on a fully automated albumin) was calculated by dividing serum analyzer. Serum glycated β-lipoprotein glycated albumin value (µmol/l) by serum was measured by agarose gel film albumin (gm/l). Similarly, glycated β- electrophoresis at pH 8.6 followed by lipoprotein/ β-lipoprotein ratio was colour development with nitro-blue calculated by dividing glycated β- tetrazolium (NBT) by a modification of lipoprotein value (µmol/l) by serum LDL staining method