Metabolic Syndrome among Indian Americans

• Metabolic syndrome (MS) is a combination of five readily measurable abnormalities associated with 2-fold risk of heart disease and 5-fold risk of diabetes.¹

• Three studies that evaluated the prevalence of MS among Asian Indians in the US found high prevalence of its various components (Table 104A).^2-4 However, the prevalence of MS ranged from 27-38%, which was similar or lower than in the US population.^2-5

 

Table 104A. Prevalence in percentage of the components and MS among Asian Indian Americans compared to people of other ethnic origin2
	AO	TG	HDL	BP	FBS	MS	Criteria
Asian Indians (Flowers)2	59	37	47	14	13	27	IDF
Asian Indians (Misra)3	61	42	38	36	63*	38/33	IDF/NCEP
Asian Indians (Palaniappan)4	NA	39	51	52	21	NA	NCEP
US population (Erwin)5	53	31	25	40	39	34	NCEP
US  Whites (Erwin)5	58	27	28	33	29	37	NCEP
US Blacks (Erwin )5	76	14	27	53	39	25	NCEP
US  Hispanics (Erwin)5	75	35	40	32	42	33	NCEP
AO, abdominal obesity; BP, blood pressure >130/85; BS, fasting blood sugar >100 mg/dl or diabetes; HDL, high density lipoprotein <40 mg/dl for males and <50mg/dl for females; IDF, International Diabetes Federation; MS, metabolic syndrome; NCEP, National Cholesterol Education Program; TG, Triglycerides >150 mg/dl; * used less reliable capillary blood and was an outlier

 

• There was a five-fold difference in the prevalence of elevated blood sugar between the studies and one study used the less accurate capillary blood sugar, which may have led to erroneous results.³ The prevalence of MS increases with age ─ doubling in people older than 60 years of age compared to those younger than 40 years.⁶

• None of the studies used the South Asian specific NCEP criteria first proposed by Enas and Mohan in 2007.¹ This criteria has become a core component of the new uniform MS definition which has finally put an end to the conflicting criteria proposed by NCEP and IDF.^7-9 (Harmonizing the metabolic syndrome (a joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and international association for the Study of Obesity). This definition is also consistent with the Indian consensus statement for the diagnosis of MS.^7-9

• A large study by Palaniappan used body mass index (BMI) rather than waist circumference (WC) and demonstrated that Asian Indians develop MS at a lower BMI than whites. In fact the prevalence of MS in Asian Indians is double that of whites at most  BMI categories and 4 times higher in those without obesity as shown in the Figure 012.⁴

• Based on these results the true prevalence of MS would have been 50% higher if the appropriate South Asian specific WC criteria were used.^{1, 7} In fact, the prevalence of MS was 41%, which was higher than in Whites (30%), Chinese (26%), and African Americans (36%) but lower than in Latinos.¹⁰

• It is worth highlighting that researchers should immediately implement the NCEP criteria using ethnic and gender specific WC for abdominal obesity, which is no longer a mandatory component of MS.^7-9

Sources

1. Enas EA, Mohan V, Deepa M, Farooq S, Pazhoor S, Chennikkara H. The metabolic syndrome and dyslipidemia among Asian Indians: a population with high rates of diabetes and premature coronary artery disease. Journal of the cardiometabolic syndrome. Fall 2007;2(4):267-275.

2. Flowers E, Molina C, Mathur A, et al. Prevalence of metabolic syndrome in South Asians residing in the United States. Metabolic syndrome and related disorders. Oct 2010;8(5):417-423.

3. Misra R, Patel T, Kotha P, et al. Prevalence of diabetes, metabolic syndrome, and cardiovascular risk factors in US Asian Indians: results from a national study. Journal of diabetes and its complications. Mar 18 2009.

4. Palaniappan L P, Wong EC, Shin JJ, Fortmann SP, Lauderdale DS. Asian Americans have greater prevalence of metabolic syndrome despite lower body mass index. International journal of obesity (2005). Aug 3 2010.

5. Ervin RB. Prevalence of metabolic syndrome among adults 20 years of age and over, by sex, age, race and ethnicity, and body mass index: United States, 2003-2006. Natl Health Stat Report. May 5 2009(13):1-7.

6. Misra  A, Wasir JS, Pandey RM. An evaluation of candidate definitions of the metabolic syndrome in adult Asian Indians. Diabetes Care. Feb 2005;28(2):398-403.

7.  Alberti KG, Eckel RH, Grundy SM, et al. Harmonizing the metabolic syndrome: a joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and international association for the Study of Obesity. Circulation. Oct 20 2009;120(16):1640-1645.

8. Misra A , Chowbey P, Makkar B. Consensus statement for diagnosis of obesity, abdominal obesity, and metabolic syndrome, for Asian Indians and recomendations for physical activity, medical and surgical management. JAPI. 2009;57:163-170.

9. Enas  EA, Singh V, Gupta R, Patel R, et al. Recommendations of the Second Indo-US Health Summit for the prevention and control of cardiovascular disease among Asian Indians. Indian heart journal. 2009;61:265-74.

10. Kanaya AM, Wassel CL, Mathur D, et al. Prevalence and correlates of diabetes in South asian indians in the United States: findings from the metabolic syndrome and atherosclerosis in South asians living in america study and the multi-ethnic study of atherosclerosis. Metabolic syndrome and related disorders. Apr 2010;8(2):157-164.