Lipid Accumulation Product: a powerful test to identify metabolic syndrome in healthy population

TAVERNA MJ, MARTÍNEZ-LARRAD T, FRECHTEL G, SERRANO-RÍOS M

Madrid

Congreso; 4th International Congress on Prediabetes and the Metabolic Syndrome; 2011

BACKGROUND & AIMS The metabolic syndrome (MS) is a cluster of cardiometabolic risk factors including central obesity, insulin resistance, hypertension, prediabetes/diabetes, and dyslipidemia. These well-known risk factors cosegregate in a subject more often than might be expected by chance, and predispose to type 2 diabetes, and appear, although controversially, to be a risk factor for cardiovascular disease (CVD) [1]. The etiology of MS is not well understood, but predisposing factors include aging, inflammation, visceral adiposity, insulin resistance, sedentary lifestyle and genetics [1]. Early and accurate detection of high-risk individuals for MS could be important to predict and prevent CVD and type 2 diabetes. Unfortunately, it has been quite difficult to identify accurate predictors for MS. Recently, we reported a strong association between LAP (lipid accumulation product), a novel index of central lipid accumulation based on a combination of waist circumference (WC) and serum triglycerides (TG), and MS defined using the NCEP/ATP III criteria (National Cholesterol Education Program/Adult Treatment Panel III, AUC-ROC 0.91), in healthy Argentinean adult males [2]. The aim of this study was to explore the LAP’s ability to diagnose MS-NCEP/ATPIII and MS-IDF (International Diabetes Federation criteria), in a sample population integrated by healthy adult males and females from Spain. SUBJECTS AND METHODS Population. This study includes cross-sectional epidemiological analyses in a sample of 768 nondiabetic unrelated Caucasian men (n = 352) and non-pregnant women (n = 416) recruited by a simple random sampling approach from a target population 63,417 inhabitants of the province of Segovia, in Central Spain (Castilla-León) [3]. It was approved by the ethic committee of our hospital. Measurements. Insulin resistance was estimated by the HOMA-IR. MS was established according to the criteria of the NCEP/ATP III (MS-NCEP/ATP III) and the IDF definition for Europid populations (MS-IDF). LAP was defined as (WC [cm] - 65) × (TG concentration [mmol/L]) for men, and (WC [cm] - 58) × (TG concentration [mmol/L]) for women [4]. LAP was created to explore the extent to which a subject had traveled the route of both increasing WC and TG. The formula includes the minimum WC values used to define sex-specific origin points (65 and 58 cm, for men and women) at NHANES III. In our sample, the minimum WC values for men (70 cm) and women (59 cm) were quite similar to those used in the original equation. The adjustment of LAP according to our minimum WC values did not change findings. For comparison purposes, we used the original formula. EWETS (Enlarged Waist Elevated Triglyceride syndrome) and HW (Hypertriglyceridemic Waist) were diagnosed as previously described [5]. RESULTS The prevalence of MS-NCEP/ATP III and MS-IDF was 15.1 and 20.5% for men respectively, and 15.4 and 17.5% for women. LAP showed the highest diagnostic accuracy for MS-NCEP/ATP III (area under the curve 0.91 and 0.90 among males and females) and MS-IDF (0.88 for both males and females). This was confirmed by internal validation using 20 000 bootstrap samples. Among males and females, different LAP cut-off values exhibited high sensitivity (78-85%) and specificity (78-85%) for MS-NCEP/ATP III and MS-IDF identification with elevated efficiency (proportion of positives and negatives classified correctly by the test=78-85%). When the sample was stratified according to decades of life, LAP exhibited a slightly lower performance among women than men, especially for MS-IDF detection. CONCLUSION In conclusion, LAP, a continuous variable associated with central lipid accumulation, has a strong and reliable diagnostic accuracy for MS-IDF and, in particular, MS-NCEP/ATP III among nondiabetic women and, especially, among men from Spain. Our results are supported by previous reports [2,4-7] and should be viewed as a basis for future prospective studies in larger sample sizes and different ethnic groups. REFERENCES 1. Gallagher EJ, LeRoith D & Karnieli E. The metabolic syndrome--from insulin resistance to obesity and diabetes. Endocrinology Metabolism Clinics of North America 37: 559-79, 2008. 2. Tellechea ML, Aranguren F, Martínez-Larrad MT, Serrano-Ríos M, Taverna MJ & Frechtel GD. Ability of lipid accumulation product to identify metabolic syndrome in healthy men from Buenos Aires. Diabetes Care 32: e85, 2009. 3. Martinez-Larrad MT, Fernandez-Perez C, Gonzalez-Sanchez JL, Lopez A, Fernandez-Alvarez J, Riviriego J, et al. Prevalence of the metabolic syndrome (ATPIII criteria). Population-based study of rural and urban areas in the Spanish province of Segovia. Medicina Clinica (Barcelona) 125: 481-6, 2005. 4. Kahn HS. The “lipid accumulation product” performs better than the body mass index for recognizing cardiovascular risk: a population-based comparison. BMC Cardiovascular Disorders 5: 26, 2005. 5. Sumner AE, Cowie CC. Ethnic differences in the ability of triglyceride levels to identify insulin resistance. Atherosclerosis 196: 696-703, 2008. 6. Kahn HS. The lipid accumulation product is better than BMI for identifying diabetes. Diabetes Care 29: 151-3, 2006. 7. Bedogni G, Kahn HS, Bellentani S, Tiribelli C. A simple index of lipid overaccumulation is a good marker of liver steatosis. BMC Gastroenterology 10: 98, 2010.