CETP and hyperinsulinemic hypoglycemia, familial, 4: The only prospective study of this association showed a low risk of CAD in Hawaiian Japanese with high HDL-C (≥60 mg/dl), irrespective of CETP deficiency.23 A large cross-sectional study of a southwest Japanese community, who underwent assessment for genetic CETP deficiency, also showed a low prevalence of coronary heart disease in participants with very high HDL-C (≥80 mg/dl).24 These studies suggest that a markedly increased level of serum HDL-C may be protective against CAD in Japanese.