Serum uric acid in metabolic syndrome.
Metabolic syndrome is wide spread among adult population in world and its prevalence increases with age. Defining the metabolic syndrome has not been an attempt to declare the existence of a new disease produced by a single pathogenesis, but rather to put together various risk factors, that as a group have a greater predictive ability for coronary heart disease. Metabolic syndrome is a cluster of risk factors which include hypertension, obesity, and dyslipidemia insulin resistance in a single patient.  It can be a signal to health care physicians that patients who present with such a cluster are at much greater danger of morbidity and mortality from Type 2 Diabetes Mellitus (T2DM) and Coronary Heart Disease (CHD). Insulin resistance is an underlying central component of the metabolic syndrome (MetS). 
Hyperuricaemia or elevated serum uric acid level (SUA) is a biochemical entity that is gaining increasing importance as it has been found by some researchers to be not only a cardiovascular risk factor but also play a role in the development of renal and metabolic diseases. [3-5] Some reports on SUA and the metabolic syndrome have noted that increased SUA concentration is associated with an increased prevalence of some of the parameters--obesity, dyslipidemia, insulin resistance and hypertension of the metabolic syndrome.  To estimate the prevalence of hyperuricemia and to study the association between uric acid levels and the various components of metabolic syndrome in age and sex matched controls and cases.
Materials and Methods
The present study was conducted on fifty (50) patients with metabolic syndrome as per IDF criteria in the outpatient department of Endocrinology, King George Hospital, Visakhapatnam. Their ages varied from 35 to 75 years (mean age--54.58). Out of 50, 32 were females, 18 were males. The study also included 30 healthy controls who were age and sex matched with the patient. The control group comprised of 16 females and 14 males. Metabolic syndrome was diagnosed based on IDF guidelines.
Inclusion Criteria: (1) Central obesity (defined as waist circumference [greater than or equal to] 90cm for men and [greater than or equal to] 80 cm for women); (2) Plus any 2 of the following 4 factors: (i) Raised triglyceride level [greater than or equal to] 150 mg/dL; (ii) Reduced HDL-C < 40 mg/dL in males, < 50 mg/dL in females; (iii) Raised BP: systolic BP [greater than or equal to] 130 or diastolic BP [greater than or equal to] 85 mm Hg; (iv) Raised fasting plasma glucose [greater than or equal to] 100 mg/dL.
Exclusion Criteria: (i) Patients with known elevated uric acid level, chronic kidney disease, haematological malignancies, hypothyroidism; (ii) Patients on treatment with drugs like salicylates, diuretics, ethambutol, pyrizinamide which causes increased serum uric acid levels; (iii) Alcoholics; (iv) Smokers.
The parameters estimated were waist circumference, blood pressure, Serum Uric acid by Uricase method and all basic investigations were done.
[FIGURE 1 OMITTED]
Present study was conducted in 50 patients of metabolic syndrome, who presented to the outpatient department of endocrinology, KGH. They were studied for serum uric acid level and its association with components of metabolic syndrome. Thirty age and sex matched healthy controls were also evaluated for comparison of serum uric acid. Mean age of patient group was 54.58. Most of them were middle aged (40-59 years of age). Two thirds of our patients (64%) were females. (Table 1 and 2)
The results obtained in the present study is Serum uric acid levels were significantly higher in patients with MS compared to healthy controls shown in table-3 and figure1. We defined hyperuricemia as SUA > 7 mg/dl in males and > 6 mg/dl in females. In various studies, significant correlations were found between serum uric acid and several components of the MS. Several possible pathophysiological mechanisms have been evoked to explain these associations including insulin resistance, the use of diuretics or impaired renal function accompanying hypertension. Insulin resistance may increase blood pressure directly via enhanced proximal tubular sodium reabsorption, or indirectly by the sympatho-adrenal system. Thereby, the kidney has been implicated as the potential link between muscle insulin resistance and compensatory hyperinsulinemia and the development of hyperuricemia and eventually hypertension. The patients showed higher serum uric acid level probably because of metabolic syndrome. Similar findings were seen in Anthonia Ogbera et al , Li-Ying Chen , Wen-Hua Zhu et al .
Serum uric acid levels were found to be increased with increase in WC as shown in table-4. So there is positive correlation between serum uric acid levels and waist circumference. This was similar to Anthonia Ogbera et al , Li-Ying Chen , Wen-Hua Zhu et al , Bedir et al  Fruehwald-Schultes et al  found that the serum uric acid concentration is independently associated with the serum leptin. Leptin could be a pathogenic factor responsible for hyperuricemia in obese patients.
In our study 24 hypertensive patients had high serum uric acid compared with non-hypertensive patients (table-5). There was significant correlation between serum uric acid level and hypertension which was similar to study by D Conen, V Wietlisbach et al , Remedios Shah . Serum uric acid concentration was found to independently correlate with hypertension. A study done by Krishnan et al.  found that men with hyperuricemia had more risk for incident hypertension. Each unit increase in serum uric acid was associated with a 9% increase in the risk for incident hypertension. Hyperuricemia is associated with deleterious effects on endothelial function, platelet adhesion and aggregation, or oxidative metabolism.
Serum uric acid levels are higher in patients of metabolic syndrome as compared to normal healthy individuals. There is significant correlation found between serum uric acid levels and hypertension. There is positive association between serum uric acid levels and waist circumference of metabolic syndrome patients. Patients with higher serum uric acid levels and its statistical significant correlation with components of metabolic syndrome is one of the risk factor in development of atherosclerosis and cardiovascular disease.
I take this opportunity to express my regards to my friend Dr K. Sameera (Assistant Professor, Katuri Medical College) for her continuous support, and constant encouragement throughout the research.
[1.] Kronenberg HM, Melmed S, Polonsky KS, Larsen PR. Williams Endocrinology. 11th Edition. Philadelphia, PA: Saunders Elsevier; 2007. p. 1524.
[2.] Yoo TW, Sung KC, Shin HS, Kim BJ, Kim BS, Kang JH, et al. Relationship between serum uric acid concentration and insulin resistance and metabolic syndrome. Circ J 2005;69:928-33.
[3.] Klein R, Klein BE, Cornoni JC, Maready J, Cassel JC, Tyroler HA. Serum uric acid. Its relationship to coronary heart disease risk factors and cardiovascular disease, Evans County, Georgia. Arch Intern Med 1973;132:401-10.
[4.] Bengtsson C, Lapidus L, Stendahal C, Waldenstrom J. Hyperuricaemia and risk of cardiovascular disease and overall death. A 12-year follow-up of participants in the population study of women in Gothenburg, Sweden. Acta Med Scand 1988;224:549-55.
[5.] Nakagawa T, Cirillo P, Sato W, Gersch M, Sautin Y, Roncal C, et al. The conundrum of hyperuricemia, metabolic syndrome, and renal disease. Intern Emerg Med 2008;3:313-8.
[6.] Ogbera AO, Azenabor AO. Hyperuricaemia and the metabolic syndrome in type 2 DM. Diabetol Metab Syndr 2010;2:24.
[7.] Chen LY, Zhu WH, Chen ZW, Di HL, Ren JJ. Relationship between hyper-uricaemia and metabolic syndrome. J Zhejiang Univ Sci B 2007;8:593-8.
[8.] Chen L, Zhu W, Chen Z, Dai H, Ren H, Chen J, et al. Relationship between hyperuricemia and metabolic syndrome. J Zhejiang Univ Sci B 2007;8:593-8.
[9.] Bedir A, Topbas M, Tanyeri F, Alvur M, Arik N. Leptin might be a regulator of serum uric acid concentration in human. Jpn Heart J 2003;44:527-36.
[10.] Fruehwald-Schultes B, Peters A, Kern W, Beyer J, Pfutzner A. Serum leptin is associated with serum uric acid concentrations in humans. Metabolism. 1999;48:677-80.
[11.] Conen D, Wietlisbach V, Bovet P, Shamlaye C, Riesen W, Paccaud F. Prevalence of hyperuricaemia and relation of serum uric acid in a developing country. BMC Public Health 2004;4:9.
[12.] Remedios C, Shah M, Bhasker AG, Lakdawala M. Hyperuricemia: a reality in the Indian obese. Obes Surg 2012;22:945-8.
[13.] Krishnan E, Kwoh CK, Schumacher HR, Kuller L. Hyperuricemia and incidence of hypertension among men without metabolic syndrome. Hypertension 2007;49:298-303.
Madhuri Swapna Yalla (1), Tadepalli Vani (1), Sujatha Pasula (2)
(1) Department of Biochemistry, Gandhi Medical College, Hyderabad, Andhra Pradesh, India
(2) Department of Biochemistry, Katuri Medical College and Hospital, Guntur, Andhra Pradesh, India
Correspondence to: Sujatha Pasula (firstname.lastname@example.org)
Received Date: 12.02.2014
Accepted Date: 26.04.2014
Table-1: Gender distribution of cases and controls Category Cases Percentage Controls Percentage Males 18 36 11 36.67 Females 32 64 19 63.33 Total 50 100 30 100 Table-2: Age wise distribution of cases and controls Age in years Cases Percentage Controls Percentage 40-49 14 28 8 26.67 50-59 23 46 14 46.67 60-69 11 22 7 23.33 69-79 2 4 1 3.33 Table-3: Comparison of various parameters of cases and controls Variable Cases Controls Mean S.D Mean S.D WC [cm] 96.42 8.478 77.60 7.010 SBP [mm Hg] 131.20 15.471 115.33 9.732 DBP [mm Hg] 85.60 6.440 79.33 2.537 SUA [mg/dl] 6.19 2.174 4.03 0.810 Variable P value WC [cm] <0.01 (Significant) SBP [mm Hg] <0.01 (Significant) DBP [mm Hg] <0.01 (Significant) SUA [mg/dl] <0.01 (Significant) Table-4: Mean serum uric acid levels in cases with increased waist circumference WC range (cm) Number of S. Uric acid (mg/dl) patients (n) 86-90 17 4.30 [+ or -] 0.810 91-95 8 5.20 [+ or -] 0.926 96-100 9 6.18 [+ or -] 1.075 101-105 7 7.04 [+ or -] 1.686 106-110 5 8.16 [+ or -] 2.016 111-115 4 10.78 [+ or -] 2.968 Table-5: Mean serum uric acid levels in cases with and without hypertension Hypertension Yes  No  S. uric acid 6.933 [+ or -] 2.548 5.038 [+ or -] 1.227 Hypertension P value S. uric acid < 0.01 (Significant)
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||RESEARCH ARTICLE|
|Author:||Yalla, Madhuri Swapna; Vani, Tadepalli; Pasula, Sujatha|
|Publication:||International Journal of Medical Science and Public Health|
|Date:||May 1, 2014|
|Previous Article:||Sexual behaviour among migrant construction workers in Indore.|
|Next Article:||A study of 25 cases of cerebral venous sinus thrombosis.|