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To investigate the relation between renal function and concentrations of lipoprotein(a) [Lp(a)] in serum, we measured Lp(a) in samples of serum and urine from patients with diabetes mellitus and in samples sent to a laboratory center for measurements of creatinine clearance. Serum Lp(a) concentrations were significantly increased in subjects with obvious renal dysfunction (serum creatinine > or = 176.8 mumol/L) compared with normal control subjects. Urinary Lp(a) excretion was decreased in subjects with obvious renal dysfunction compared with subjects without obvious renal dysfunction (serum creatinine < or = 88.4 mumol/L) and was negatively and positively correlated with serum creatinine and creatinine clearance, respectively. More than 80% of urinary Lp(a) was recovered in the d > 1.21 kg/L fraction. At least six bands for apolipoprotein(a) [apo(a)] fragments, which were smaller than native apo(a) in serum, were observed in urine by immunoblotting, and some of these were also detected in serum. Degraded apo(a) fragments are probably present in urine, and their excretion decreases in parallel with decreases in the glomerular filtration rate.

The present study was undertaken to evaluate the effects of physical exercise on plasma lipoprotein and apolipoprotein metabolism in elderly men. We measured plasma concentrations of lipids, lipoproteins, and apolipoproteins (apo) in 12 elderly runners (OR), 12 elderly sedentary controls, 16 young runners (YR), and 15 young sedentary controls. Although there were no significant differences in plasma levels of cholesterol (Ch), triglyceride, and phospholipid between two old groups and between two young groups, OR and YR had decreased levels of VLDL-Ch (42% and 59% of respective control) and LDL-Ch (90%, 94%), and increased levels of HDL-Ch (133%, 112%), apo A-I (109%, 101%), and apo A-II (109%, 105%). These data indicate that physical exercise may have favorable effects on plasma concentrations of lipoproteins and apolipoproteins in OR as well as in YR, and affect HDL-lipids, HDL-proteins, and ratio of HDL-proteins/HDL-lipids.

This study examined the relation of training distance to plasma high density lipoprotein cholesterol (HDLC) concentration in runners. Forty-eight male endurance runners, aged from 30 to 57 years, were classified into three groups according to training distance (Grade I: n = 12, 30 km/week; Grade II: n = 22, 60 km/week; Grade III: n = 14, 100 km/week in average running distance), with 12 non-lean and 12 lean subjects as age-matched untrained controls. There were no significant differences in plasma total cholesterol among the groups (194-208 mg/dl on average). HDLC level was significantly higher in the untrained, lean group than in the untrained, non-lean men (63 +/- 13 vs. 46 +/- 8 mg/dl, mean +/- SD). HDLC levels in all the runner groups were significantly higher than in untrained, lean subjects, and no differences were observed among Grade I, II and III runner groups (76 +/- 15, 76 +/- 13, 77 +/- 11 mg/dl, respectively). This study suggests that further increases in HDLC could not occur in response to further elevation of training distance in well-trained runners.