In a study of 591 consecutive coronary patients, we identified 243 (41%) with low high-density lipoprotein (HDL) cholesterol <35 mg/dl and demonstrated the benefits of vigorous nonpharmacologic therapy with cardiac rehabilitation and exercise training in this subgroup. However, patients with low HDL and "normal" triglycerides have significantly greater improvements in low-density lipoprotein (LDL) cholesterol and LDL/HDL ratio than patients with low HDL cholesterol and hypertriglyceridemia who are more likely to require drug treatment.