This observational study aims to look at the connections between kidney stones, insulin resistance, and inflammation. The researchers hypothesize that people who form calcium kidney stones and have insulin resistance may have higher levels of inflammation because they have more visceral fat (fat around the abdominal organs). The study will recruit 20 people who have had calcium kidney stones but don't have diabetes, and 20 healthy people who haven't had kidney stones. All the participants will come to the research center at the University of Chicago Medicine. Participants will have a dual-energy X-ray absorptiometry (DEXA) scan to measure their visceral fat, and give blood and urine samples. The blood will be tested for insulin resistance, inflammatory markers, and other metabolic factors. The urine will be analyzed for substances that increase kidney stone risk. The main goal is to see if the kidney stone formers with insulin resistance have more visceral fat compared to those without insulin resistance and the healthy participants. The researchers will also compare inflammatory marker levels between groups, and look at how visceral fat, inflammatory markers, insulin resistance, and urine stone risk factors are related. The findings may help explain how kidney stones are connected to metabolic conditions like diabetes and cardiovascular disease. Researchers hope this information will help identify stone formers at risk early and develop preventive treatments in the future.