Microalbuminuria among diabetic patients with the Metabolic Syndrome

Microalbuminuria, an important component of the Metabolic Syndrome, has been found to predict mortality from cardiovascular disease among diabetic patients. We determine the prevalence of microalbuminuria among patients with type 2 diabetes with and without the Metabolic Syndrome. Microalbuminuria was more common among patients with the Metabolic Syndrome than in those without (45% vs 21%, respectively, p<0.05). Introduction Microalbuminuria may be defined as an urinary albumin excretion rate >20 μg/min or albumin creatinine ratio (ACR) >30 mg/g.1 It has been shown to predict the development of diabetic nephropathy among patients with type 2 diabetes. Microalbuminuria has been related to insulin resistance and can occur prior to the onset of diabetes.2 Clinical trials showed improved cardiovascular risk and reduced microalbuminuria with the use of agents that affect the renin-angiotensin system.3 There has been much debate as to whether microalbuminuria should be included as a major component of the Metabolic Syndrome. We determine the prevalence of microalbuminuria among patients with type 2 diabetes with and without Metabolic Syndrome. Patients and methods One hundred and ninety-two (192) patients with type 2 diabetes between the ages of 30 and 70 years, attending the Diabetic Clinic of Lagos University Teaching Hospital (LUTH), Lagos, Nigeria, were randomly selected for the study after informed consent was obtained. The diagnosis of Metabolic Syndrome was made based on the World Health Organization (WHO) criteria1 of the presence of type 2 diabetes, systemic hypertension (BP O S Adediran, Department of Medicine, College of Health Sciences, Benue State University, Makurdi, Nigeria; A K Jimoh, Department of Chemical Pathology, University of Ilorin Teaching Hospital, Ilorin, Nigeria; A E Edo, Department of Medicine, University of Benin Teaching Hospital, Benin, Nigeria; and A E Ohwovoriole, Department of Medicine, Lagos University Teaching Hospital, Lagos, Nigeria. Correspondence to: Dr OS Adediran, Department of Medicine, College of Heath Sciences, Benue State University, Markurdi, Nigeria. Email: [email protected] ≥140/90 or patients on anti-hypertensive medication), and obesity (body mass index ≥30 kg/m2 and/or waist to hip ratio in males ≥0.9, in females ≥0.85). Urine samples were collected for the spot assessment of the urinary microalbuminuria using the Micral test strip, a semiquantitative method for the assay of microalbuminuria. An albumin concentration detection over 20 mg/l is considered consistent with microalbuminuria (albumin excretion >30 mg/day). Results Half of the 192 patients (96) studied were diagnosed with Metabolic Syndrome, out of which 61 were females. Forty-seven (47) of the control subjects were females. Patients with Metabolic Syndrome were older (mean age 58±12 years) than the control subjects (mean age 52±15 years). The duration of diabetes was longer in patients with Metabolic Syndrome than the control subjects (7±5 vs 6±4 years, respectively p<0.05). Forty-five per cent (45%) of those with Metabolic Syndrome had microalbuminuria compared to 21% of those without (p<0.05) (see Table 1). Furthermore, abnormal ECG findings were more common among the Metabolic Syndrome patients (see Table 1). Systolic BP was classed as unsatisfactory (≥140 mmHg) in 56% of Metabolic Syndrome patients with microalbuminuria, while 51% also had an unsatisfactory (≥90 mmHg) diastolic BP. None of the control subjects was hypertensive. The mean systolic and diastolic BP were 163±31 mmHg and 93±15 mmHg for Metabolic Syndrome patients with microalbuminuria, while the control subjects had values of 119±22 mmHg and 72±13 mmHg respectively. Discussion The prevalence of microalbuminuria was higher among patients with Metabolic Syndrome (45%) than the controls (21%). The higher prevalence could be due to the fact that microalbuminuria is a major predictive index for cardiovascular mortality.2 Mykkanen et al3 reported a prevalence of 28% among patients with type 2 diabetes, which is similar to the figure obtained from this study. The duration of diabetes was higher among patients with Metabolic Syndrome. This may lead to an increase in the duration of oxidative stress on the vascular system, thereby making them more prone to the development of microalbuminuria. Microalbuminuria occurrence is also proportional to increased levels of both systolic and diastolic BP. High BP has been identified as a cause of oxidative stress and endothelial dysfunction in the