Role of insulin resistance in uric acid nephrolithiasis

Table 2 Insulin resistance and uric acid stone formation

Ref.	Type	Year	n	Study population	Relevant variables	Conclusion
Lieske et al[30]	Retrospective, Case Control, single county in Minnesota	2006	7122	Known stone former vs Control	Stone analysis, metabolic evaluation	DM, obesity, and HTN are associated with the development of kidney stones. DM is significantly associated with UA stone formation
Daudon et al[10]	Cross-sectional	2006	2464	DM vs Non-DM stone formers	Stone analysis, BMI, clinical and lab data in a subset of stone formers	DM is associated with a higher overall frequency of kidney stones, specifically, UA. UA stone formation can reflect IR and patients should be evaluated for MetS and/or DM if UA stones are diagnosed.
Akman et al[11]	Retrospective, single institution	2012	146	MetS vs Non-MetS undergoing PCNL	Kidney stone analysis, imaging for initial/recurrent kidney stone diagnosis, baseline blood chemistry and urinalysis	Patients with MetS have a higher frequency of UA stones (21.9% vs 4.1%) and a higher rate of all stone recurrence following PCNL
Cho et al[12]	Retrospective, three institutions	2012	712	MetS vs Non-MetS undergoing endourologic intervention for stones	Stone analysis, metabolic data, International Diabetes Federation definition for MetS	MetS, specifically the traits of impaired fasting glucose and hypertriglyceridemia, is significantly associated with UA stone formation, but calcium based stones remain most common in this group
Kadlec et al[31]	Retrospective, single institution	2012	590	All stone formers undergoing endourologic intervention	Stone analysis, MetS factors (presence of obesity, DM, HTN, and HL)	DM and HTN, components of MetS, are significantly associated with UA containing stones
Stansbridge et al[32]	Retrospective, single institution	2013	1504	UA stone formers vs Non-UA	24H urine, stone analysis, relevant underlying diagnoses, including DM	UA containing stones are increased in DM, but calcium containing stones are still the most common in DM
Inci et al[33]	Case-control, single institution	2012	99	Control vs Stone formers (sub-stratified by stone type)	Stone analysis, metabolic evaluation	BMI and Hyperlipidemia, two major traits of IR/MetS, are significantly associated with calcium and UA stone formation
Zhou et al[34]	Retrospective, single institution	2013	269	UA stone formers vs Non-UA stone formers undergoing PCNL	CT for visceral fat area measurement, stone analysis, metabolic evaluation	HTN and visceral fat area, two traits highly associated with IR/MetS, are independent risk factors associated with UA stone formation

IR: Insulin resistance; MetS: Metabolic syndrome; DM: Diabetes Mellitus; UA: Uric acid; HTN: Hypertension; PCNL: Percutaneous nephrolithotomy.