Metabolic Syndrome:  This is also sometimes called Syndrome X.  It refers in particular to overweight people whose bodies are resistant to the effects of insulin.  People with the metabolic syndrome are at high risk for developing diabetes.  Common clinical traits are obesity, high triglyceride levels, low HDL ("good cholesterol"), fasting blood sugar above 110, and elevated blood pressure. 

Relationship To Kidney Stones: The metabolic syndrome is associated with low urine pH (acidic urine) and citrate levels.  Research has shown that heavier people have lower urine pH values.  This increases the risk for kidney stones.  For those with uric acid stones, high doses of citrate and other medications may be necessary to raise the urine pH. 

Diabetes:  Diabetes is most often associated with insulin resistance.  The body is insensitive to the effects of insulin.  In many diabetics, especially early in the disease, blood insulin levels are actually elevated.  Diabetics also have low urine pH values which leads to stones.  Diabetes over time can lead to high blood pressure and kidney damage.  The preferred medications for diabetes and/or the presence of kidney damage will complicate treatment of stones in this group.  Potassium citrate is not always safe to administer.  Sometimes only sodium citrate can be used or acetazolamide must be prescribed.  Both of these medications increase urine pH which helps prevent or dissolve uric acid stones.