Metabolic Syndrome

Metabolic syndrome

pediatric definitions of metabolic syndrome: need 3 of the following (based on adult definitions, but similar approach in peds)

no consensus on a single definition
no specific drug tx for insulin resistance or “metabolic syndrome” is currently approved (2009) for children or teens
association between obesity, insulin resistance and other “metabolic syndrome” phenotypes, and PCOS and NAFLD (non-alcoholic fatty liver disease)
obesity and insulin resistance are factors in pro-thrombotic and pro-inflammatory tendencies that increase the risk of cardiovascular disease.
Waist circ is a surrogate for visceral fat

Pathophysiology

adipocytes are an endocrine organ, producing cytokines and hormones involved in energy balance, glucose homeostatis and inflammation.
Vicious cycle: incr adipocytes -> incr cytokines/hormones -> incr insulin resistance -> incr insulin secrtion -> incr appetite -> incr wt. gain

Pediatric Definitions of Metabolic Syndrome

	Cook et al 2008	Cruz et al 2004	Caprio 2005	Joliffe/Jansen 2007
Abd Obesity	Waist >= 90%ile	Waist >= 90%ile	BMI z >=2.0	Waist>=92nd %ile (boys) Waist >= 72nd %ile (girls)
Elev BP	SBP or DBP >=90%ile	>= 95th	>= 95th	Boys: SBP>=92nd %ile or DBP >=97%ile Girls: SBP>=93rd %ile or DBP >=99%ile
High TG	>=110 mg/dL	>=95%ile	>=95%ile	Boys: TG >89%ile Girls: TG >=89%ile
Low HDL	<= 40	<= 5th %ile	<= 5th %ile	<= 26th %ile (boys) <=43rd %ile (girls)
Impair fasting glucose	>=100	Impaired glucose tolerance. >140, but <200 at 2 hr	Impaired glucose tolerance. >140, but <200 at 2 hr	>=100

Adult waist circ thresholds may be used for adolescent reference. Increased risk for health problems if:

Cardiometabolic Conditions Related to Obesity

Obesity or normal wt, Oligo- or amenorrhea, Hirsutism
Lab: elev free testosterone, insulin resistance
US: polycystic ovaries
In adults w/ metabolic syndrome and PCOs, metformin has been used; though not established yet in adol patients.

Fasting lipid panel: high TG, low HDL with obesity
Very high total chol and LDL more sugg of genetic/familial origin but prevalence of obesity could lead to unrelated co-occurrences

From Adolescent Health Update Feb 2009. Megal Gabel MD and Stephen Cook MD, MPH, FAAP. From AAP Adol Health Section, sponsored by Merck.