Prevalence of metabolic syndrome in adolescents: Reason to worry.

Sir,

We read with interest the article ‘Prevalence of metabolic syndrome in adolescents aged 10-18 years in Jammu, J and K’ by Singh et al.,[1] and would like to make some important comments.

The metabolic syndrome (MS) in adolescents is a largely unrecognized health problem and it's exact prevalence in developing countries particularly in India is unknown until recently when few studies were conducted in this field including that by Singh et al.[1] Kapil et al.,[2] found that the prevalence of MS in children (6-18 years) from high income group in Delhi was 6.5% (males 6.9% and females 5.9%), which was higher than that reported by Singh et al.[1] Recently, Tandon et al.,[3] studied the prevalence of MS in urban Indian adolescents (695 out of 15,101 adolescents, 10-18 years) and found that the calculated prevalence of MS in total population was 4.3% and 3.0% using Adult Treatment Panel (ATP) and international diabetes federation criteria, respectively, which was slightly higher than that reported by Singh et al.[1] MS was significantly higher in girls than boys and the most common component of MS was central obesity followed by hypertriglyceridemia, low high density lipoprotein (HDL)-cholesterol, hypertension and dysglycemia; which were in contrast to that reported by Singh et al.,[1] where males had higher prevalence; and low HDL-cholesterol was most common and high blood pressure was least common constituent of MS. Moraes et al.,[4] conducted a systematic review by including 8 studies in adolescents (10-19 years) undertaken in low to medium-income countries and found that the prevalence of MS ranged from 4.2-15.4 in studies using the NCEP-ATP III criteria; and 4.5-38.7 in studies using the WHO criteria.

WHO criteria for MS include Insulin resistance (defined as 1 of the following: Type 2 diabetes; impaired fasting glucose; impaired glucose tolerance; or for those with normal fasting glucose values (<110 mg/dL), a glucose uptake below the lowest quartile for background population under hyperinsulinemic, euglycemic conditions) AND two of the following: Antihypertensive medication and/or high blood pressure (≥140 mm Hg systolic or ≥90 mm Hg diastolic); plasma triglycerides ≥150 mg/dL; HDL-cholesterol <35 mg/dL in men or <39 mg/dL in women; BMI >30 kg/m2 and/or waist: Hip ratio >0.9 in men, >0.85 in women; and urinary albumin excretion rate ≥20 μg/min or albumin: creatinine ratio ≥30 mg/g.[5] The WHO criteria is more objective than ATP III criteria, but it requires special testing of glucose status beyond routine clinical assessment,[5] which makes it less preferred tool for epidemiological studies.

The difference in prevalence of MS and varied prevalence of different components of MS in different studies may be due to differences in populations studied and different criteria used. MS in adolescents is an under recognized and is a forerunner of diabetes mellitus and cardiovascular diseases in adulthood. Therefore, its urgent identification and interventions with lifestyle changes are needed to prevent disease progression into adulthood.