Metabolic Syndrome (Syndrome X; Insulin Resistance Syndrome) By Adrienne Youdim, MD, David Geffen School of Medicine at UCLA Reviewed / Revised Aug 2021 | Modified Sep 2022 View Patient Education Diagnosis Treatment Key Points Topic Resources Criteria Often Used for Diagnosis... Metabolic syndrome is characterized by a large waist circumference (due to excess abdominal fat), hypertension, abnormal fasting plasma glucose or insulin resistance, and dyslipidemia.