Table 1. Summary of major studies reporting association of metabolic syndrome and nephrolithiasis.

Author	Risk factor(s) studied	Type of study	Patients population	Follow-up	Results
Reiner (10)	Atherosclerosis	Observation	5,115 adults (18 to 30 years)	20 years	3.9% with symptomatic stones OR 1.6 develop atherosclerosis
Rule (15)	MI	Cohort	4,564 stone formers vs. 10,089 non-stone formers	9 years	OR for MI—1.35
West (12)	MS	NHANES III	33,994 persons	N/A	Stones present Zero—3% Three—7.5% Five—9.8% Four traits → 2X odds of stones
Kohjimoto (11)	MS	Population: Japanese	11,555 persons	N/A	Recurrent multiple stones present with traits Zero—57.7% One—61.7% Two—65.2% Three—69.3% Four—73.3%

MS, metabolic syndrome; NHANES, National Health and Nutrition Examination Survey; N/A, not applicable; MI, myocardial infarction.