Serum Lp(a) lipoprotein concentrations in insulin dependent diabetic patients with microalbuminuria

UK Prospective Diabetes Study (UKPDS). X. Urinary albumin excretion over 3 years in diet-treated type 2, (non-insulin-dependent) diabetic patients, and association with hypertension, hyperglycaemia and hypertriglyceridaemia

Urinary albumin excretion has been assessed in 585 newly-presenting Type 2 (non-insulin-dependent) diabetic patients (aged 53 (8) years, 67% male) at diagnosis with fasting plasma glucose 10.3 (3.2) mmol/l and over 3 years of dietary treatment. Urinary albumin at diagnosis, geometric mean (1 SD interval) corrected for dilution by regression on urine creatinine concentration of 10 mmol/l, was 17 (5-58) mg/l compared with 8 (3-18) mg/l in an age-matched non-diabetic reference population. Values greater than 50 mg/l were found in 17% of diabetic patients compared with 4% in the reference group. After diet therapy for 3 months, fasting plasma glucose decreased to 6.9 mmol/l and urinary albumin to 12 (4-31) mg/l (p < 0.0001). This suggests that increased urinary albumin excretion at diagnosis is in part functional, possibly secondary to glomerular hyperfiltration caused by hyperglycaemia and raised blood pressure. Over the next 3 years, mean fasting plasma glucose was 7.2 mmol/l, albumin excretion changed little, without significant increase either in patients with raised or normal albumin at diagnosis. Both at diagnosis and over 3 years, urinary albumin excretion was independently associated with fasting plasma glucose and triglyceride levels and with systolic blood pressure, but the combination of these factors only explained 10% of the total variance. This suggests the presence of additional pathological processes in patients with increased urinary albumin. Urinary albumin was not associated with other variables included in syndrome X, such as HDL cholesterol, fasting plasma insulin, obesity or central adiposity.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship of progressively increasing albuminuria to apoprotein(a) and blood pressure in type 2 (non-insulin-dependent) and type 1 (insulin-dependent) diabetic patients

This study has explored the temporal relationship between apoprotein(a), blood pressure and albuminuria over a mean interval of 11 years in a cohort of 107 diabetic patients of whom 26 (14 Type 2 (non-insulin-dependent), 12 Type 1 (insulin-dependent) had progressively increasing albuminuria ('progressors'). In Type 2 diabetic patients, no significant differences were noted for HbA1, blood pressure, creatinine clearance or serum lipids between progressors and non-progressors. In Type 1 diabetic patients, final systolic and diastolic blood pressures were higher in progressors compared with non-progressors and progressors showed impairment of renal function in association with a rise in blood pressure at the macroalbuminuric stage. Initial apoprotein(a) levels were similar in progressors and non-progressors of either diabetes type. Apoprotein(a) levels increased exponentially with time in 12 of 14 Type 2 progressors but only in 5 of 12 Type 1 progressors (p < 0.01). In Type 2 diabetic patients, the annual increase in apoprotein(a) levels was 9.1 +/- 2.4%, which was significantly greater than in non-progressors, 2.0 +/- 1.2% (p < 0.01) and also exceeded the rates of increase of apoprotein(a) in progressors with Type 1 diabetes, 4.0 +/- 1.4%, (p < 0.05). Apoprotein(a) levels correlated significantly with albuminuria in 8 of 14 Type 2 progressors but only in 3 of 12 Type 1 progressors (p < 0.05). The rate of increase of apoprotein(a) levels was not related to mean HbA1, creatinine or creatinine clearance levels, or to albuminuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipoprotein(a) levels in relation to diabetic complications in patients with non-insulin-dependent diabetes

The relationship between serum levels of lipoprotein(a) Lp(a)) and the presence of chronic diabetic complications was studied in 194 patients with non-insulin-dependent diabetes mellitus (NIDDM; 75 males, 119 females; age 66 +/- 11 years; duration of diabetes, 11 (range 1-35) years). They were taking various treatments (diet alone, oral hypoglycaemic agents and/or insulin). Metabolic status and prevalence of diabetic complications were assessed by detailed history, physical examination, laboratory analysis and ECG. Average metabolic control was moderate (HbA1c 8.2 +/- 1.7%). Median serum Lp(a) level was 183 U l-1 (range 8-2600 U l-1), which was significantly higher than in control subjects of comparable age (median 101; range 8-1747 U l-1; P < 0.05), while HDL-cholesterol levels were lower (1.14 +/- 0.38 vs. 1.35 +/- 0.35 mmol l-1; P = 0.001), and total cholesterol levels were comparable. No significant relationships between diabetes treatment or metabolic control and Lp(a) levels were observed. In the quartile of patients with the highest Lp(a) levels, total cholesterol and triglycerides were slightly higher (P < 0.05), whereas HDL-cholesterol was not different. With increasing Lp(a) levels, higher prevalences of preproliferative retinopathy and of coronary artery disease (CAD) were observed, but not of the other complications. No relationship was found between the degree of albuminuria and Lp(a) levels. We conclude that in NIDDM patients, Lp(a) levels are elevated compared with non-diabetic subjects, and that higher Lp(a) levels are associated with higher prevalences of CAD and of retinopathy.

The effect of microalbuminuria on glycaemic control, serum lipids and haemostasis parameters in non-insulin-dependent diabetes mellitus

Microalbuminuria is an important risk factor for cardiovascular disease in non-insulin-dependent diabetes mellitus (NIDDM) patients although the pathogenic mechanism between microalbuminuria and cardiovascular disease has not yet been established. Microalbuminuria in insulin-dependent diabetes mellitus (IDDM) patients has been related to abnormalities in haemostasis, poor glycaemic control, disadvantageous alterations in the lipid spectrum and elevated concentrations of lipoprotein(a), another independent risk factor for cardiovascular disease. In this study the interrelations between microalbuminuria and metabolic control, lipoprotein(a), other blood lipids and several haemostasis parameters were studied in 96 NIDDM patients (50 women, 46 men). Forty-three patients showed microalbuminuria. No significant differences were found in blood lipids (Lp(a), serum cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol and triglycerides), glycaemic control (HbA1c) and several haemostasis parameters (factor VII, VIII, fibrin monomer, thrombin-antithrombin III, D-dimer, tissue plasminogen activator antigen and plasminogen activator inhibitor-1) between the micro- and normoalbuminuric subgroups. In the microalbuminuric subgroup increased concentrations for plasminogen and alpha 2-antiplasmin were measured. In general, the presence of microalbuminuria was not associated with significant alterations in glycaemic control, blood lipids or haemostasis parameters in this group of 96 NIDDM patients. Further investigation is required to explain the excess cardiovascular mortality in patients with an elevated urinary albumin excretion rate.

Changes in fibrinolytic parameters in male patients with type 2 (non-insulin-dependent) diabetes mellitus

We examined changes in fibrinolytic parameters in male patients with diabetes mellitus (DM) and controls. DM patients were divided into three groups: patients without retinopathy, patients with simple retinopathy, and patients with proliferative retinopathy. Plasma levels of t-PA (tissue plasminogen activator) and t-PA-PAI-1 (plasminogen activator inhibitor-1) complex increased with increase in age, but those of PAI-1 (total and free) did not change in controls. On the other hand plasma levels of PAI-1 decreased with increase in age in DM patients. Plasma levels of t-PA, t-PA-PAI-1 complex, free and total PAI-1 increased with increase in body mass index in controls, but no significant changes were shown in these parameters in DM patients. When compared with controls, plasma levels of t-PA, t-PA-PAI-1 complex and PAI-1 were lower in DM patients. Plasma levels of UK (urokinase) and Lp(a) were higher in DM patients. ELT (euglobulin clot lysis time) was significantly shorter in DM patients than in controls. Patients without retinopathy showed increased fibrinolytic activities compared with those with retinopathy due to the increased levels of t-PA in plasma. These results seem to indicate that blood vessels release larger amounts of t-PA at the early stage of DM, then release being impaired at its advance stage. It is also suggested that the regulatory control mechanisms of fibrinolytic activity associated with mechanisms of fibrinolytic activity associated with change in age and body mass index are different between patients with DM and normal people.

Altered regulation of cholesterol metabolism in type I diabetic women during the menstrual cycle

This study examines the relationship of cellular cholesterol metabolism to oestrogen and progesterone during the menstrual cycle in diabetic and non-diabetic subjects. Nine premenopausal diabetic women were compared to nine non-diabetic women of the same age. Oestrogen, progesterone, lipoproteins, including lipoprotein (a) (Lp(a)) and cholesteryl ester transfer protein (CETP) were determined in serum. Cellular cholesterol content and cellular cholesterol synthesis were measured in mononuclear leucocytes. There was no significant change in serum lipoproteins including Lp(a) during the cycle in either group. CETP activity was significantly higher over the 4 weeks in the diabetic patients compared with non-diabetic subjects (mean 463 +/- 30 mumol l-1 h-1 vs 405 +/- 28 mumol l-1 h-1, p < 0.01). Serum high density lipoprotein (HDL) cholesterol was significantly lower during the 4 weeks in the diabetic patients (1.7 +/- 0.1 mmol l-1 vs 1.8 +/- 0.1 mmol-1, p < 0.05). Cellular cholesterol synthesis decreased steadily up to the third week in cells from the control subjects whereas there was no significant change in cells from diabetic patients whose cellular cholesterol synthesis was higher at week 3 compared with non-diabetic subjects (663 +/- 54 nmol mg-1 cell protein vs 432 +/- 43 nmol mg-1 cell protein, two-way interaction p < 0.05). There was a significant negative correlation between cellular cholesterol synthesis and serum oestrogen in the non-diabetic subjects (p < 0.05) but not in the diabetic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholesterol: a renal risk factor in diabetic nephropathy?

In a prospective follow-up of 30 patients with type 1 diabetes and nephropathy, serum cholesterol, triglycerides, apolipoprotein Al and B, and lipoprotein(a) were determined to study their relationship to the rate of decline in glomerular filtration rate. The patients had proteinuria and advanced nephropathy with a mean +/- SD glomerular filtration rate of 39 mL/min/1.73 m2. The decline in glomerular filtration rate was determined during 2.5 +/- 0.5 years. High serum cholesterol, triglycerides, and apolipoprotein B were correlated to a more rapid deterioration in kidney function. The rate of decline in glomerular filtration rate was 1.0 +/- 2.5 mL/min/yr in the 10 patients with the lowest cholesterol level, compared with 4.5 +/- 3.2 mL/min/yr in the patients with the highest serum cholesterol (P = 0.015). The combined effect of the measured lipids, blood pressure, type of antihypertensive treatment, protein intake, proteinuria, and hemoglobin A1C on the rate of decline in glomerular filtration rate was assessed by multiple regression analysis. The measured factors together had a high explanatory power for the rate of decline in glomerular filtration rate. In this model, 73% of the variation in decline in glomerular filtration rate was explained by the measured variables (multiple r2 = 0.73). Low cholesterol and treatment with an angiotensin-converting enzyme inhibitor were the strongest predictors of a favorable renal prognosis. This suggests that hypercholesterolemia is an important risk factor for diabetic nephropathy.

Lipoprotein(a) in patients treated by continuous ambulatory peritoneal dialysis

Lipoprotein(a) [Lp(a)] has been identified as an independent, inherited risk factor for atherosclerotic vascular disease. An elevation of Lp(a) plasma levels has been documented in several series of uremic patients submitted to maintenance dialysis treatment methods or after renal transplantation. We have measured the plasma levels of Lp(a) using an enzyme-linked immunosorbent enzyme method in 19 patients treated with continuous ambulatory peritoneal dialysis (CAPD). Mean (+/- SD) concentration of Lp(a) was significantly higher in the patients than in the 19 healthy controls (51 +/- 48 mg/dL v 16 +/- 15 mg/dL, P < 0.005). No significant differences in Lp(a) levels were found between diabetic patients (n = 5) and nondiabetic patients (n = 14) or between patients who had (n = 6) or had not (n = 13) suffered a previous major cardiovascular complication. No correlation was evident between Lp(a) levels and the patients' ages, period of time on CAPD treatment, or any other lipid-lipoprotein investigated parameter. The mechanisms accounting for the elevation of Lp(a) levels in CAPD patients as well as the specific value of increased Lp(a) concentration as a cardiovascular risk predictor in uremic patients remain thus far speculative. Additional experimental and clinical studies are warranted before the administration of drugs to attempt to lower Lp(a) levels in CAPD patients can be recommended.

Apolipoprotein(a) and atherogenesis

Lipoprotein(a) (Lp(a)) consists of a unique apolipoprotein, apolipoprotein(a), (apo(a)) linked by a disulphide bridge to apolipoprotein B of low density lipoprotein (LDL). Apo(a) is homologous with plasminogen and exhibits genetic polymorphism with the commoner phenotypes due to larger forms being associated with lower plasma levels and the less common phenotypes associated with smaller forms and higher plasma levels. The later are more common in patients with macrovascular disease. In a study of 6448 patients with established coronary heart disease we found that 43% had apo(a) levels above 300 units/litre and 10% had levels above 1000 units/litre and a geometric mean of 201 units/litre in contrast to 140 normal controls in whom 25% exceeded 300 units/litre, 1% exceeded 1000 units/litre and the geometric mean was 107 units/litre. Amongst patients with cholesterol levels < 5.5 mmol/L undergoing coronary artery surgery were patients with low HDL levels and raised apo(a) levels who would not be identified in screening focusing primarily on total cholesterol. In patients with both insulin dependent and non insulin dependent diabetes mellitus those with microalbuminuria or albuminuria (known to be at high risk for macrovascular disease) had apo(a) levels comparable to non diabetic patients with coronary artery disease while diabetic patients without microalbuminuria had normal levels of apo(a). It is likely that apo(a) has a role in the accelerated macrovascular disease in diabetic patients with renal disease.

Improved blood glucose control by insulin therapy in type 2 diabetic patients has no effect on lipoprotein(a) levels

The effects of improved blood glucose control by insulin therapy on lipoprotein(a) and other lipoproteins were studied in 54 patients with Type 2 diabetes (mean +/- SD: age 67 +/- 9 years, body mass index 26.1 +/- 4.4 kg m-2, median duration of diabetes 10 (range 1-37) years, 23 males, 31 females), who were poorly controlled despite diet and maximal doses of oral hypoglycaemic agents. After 6 months of insulin treatment, mean fasting blood glucose concentrations had decreased from 14.1 +/- 2.2 mmol l-1 to 8.4 +/- 1.8 mmol l-1 (p < 0.001), and HbA1c had fallen from 11.1 +/- 1.4% to 8.2 +/- 1.1% (p < 0.001). Significant decreases of total and LDL cholesterol, triglycerides, apolipoprotein B, and free fatty acids were observed, while HDL-cholesterol and apoA1 increased by 10%. Baseline serum Lp(a) levels were elevated compared to non-diabetic subjects of similar age (median 283, range 8-3050 mg l-1, vs 101, range 8-1747 mg l-1, p < 0.05), but did not change with insulin, and there was no correlation with the degree of metabolic improvement and changes in Lp(a) levels. It is concluded that improved blood glucose control by insulin therapy does not alter elevated Lp(a) levels in Type 2 diabetic patients, but has favourable effects on the other lipoproteins.

Apolipoprotein E phenotype is related to macro- and microangiopathy in patients with non-insulin-dependent diabetes mellitus

The role of apoliprotein E (apo E) in modulating the susceptibility of individuals with non-insulin-dependent diabetes mellitus (NIDDM) to atherosclerotic vascular disease was studied in 143 male and 128 female patients with NIDDM. The data show that the apolipoprotein phenotype E2 somehow protects from macrovascular complications in NIDDM both in men and women. E2 also tends to protect from microvascular complications. In contrast, apo E phenotypes E4/4 and E4/3 tend to increase the risk for macroangiopathy in NIDDM patients. The lower prevalence of macroangiopathy in the subjects with E2 was associated with lower plasma total and LDL cholesterol concentrations and low plasma lipoprotein(a) levels. Overall, this study demonstrates the role of the apo E phenotype to modulate the risk for diabetic complications in patients with NIDDM. The confirmation of the association of apo E polymorphism with diabetic complications warrants, however, long-term follow-up studies.

Apolipoprotein(a) and cardiovascular disease in type 2 (non-insulin-dependent) diabetic patients with and without diabetic nephropathy

The relative mortality from cardiovascular disease is on average increased five-fold in Type 2 (non-insulin-dependent) diabetic patients with diabetic nephropathy compared to non-diabetic subjects. We assessed the possible contribution of dyslipidaemia in general and elevated serum apolipoprotein(a) (apo(a)) in particular. Type 2 diabetic patients with normo-, micro- and macroalbuminuria were compared with healthy subjects. Each group consisted of 37 subjects matched for age, sex and diabetes duration. Serum creatinine in the nephropathy group was 105 (54-740) mumol/l. The prevalence of ischaemic heart disease (resting ECG, Minnesota, Rating Scale) was 57, 35, 19 and 2% in macro-, micro- and normoalbuminuric diabetic patients and healthy subjects, respectively. The prevalence of ischaemic heart disease was higher in all diabetic groups as compared to healthy subjects (p < 0.05), and higher in macroalbuminuric as compared to normoalbuminuric diabetic patients (p < 0.01). There was no significant difference between apo(a) in the four groups: 161 (10-1370), 191 (10-2080), 147 (10-942), 102 (10-1440) U/l (median (range)) in macro-, micro- and normoalbuminuric groups and healthy subjects. Serum total-cholesterol, HDL-cholesterol and LDL-cholesterol were not significantly different when comparing healthy subjects and each diabetic group. Apolipoprotein A-I was lower (p < 0.05) in all diabetic groups as compared to healthy subjects (nephropathy vs healthy subjects): 1.50 +/- 0.25 vs 1.69 +/- 0.32 g/l (mean +/- SD). Triglyceride was higher (p < 0.05) in patients with nephropathy and microalbuminuria as compared to healthy subjects (nephropathy vs healthy subjects): 2.01 (0.66-14.7) vs 1.09 (0.41-2.75) mmol/l (median (range)).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular risk factors in non-insulin-dependent diabetic subjects with microalbuminuria

In subjects with insulin-dependent diabetes mellitus, microalbuminuria has been associated with increased triglyceride and lipoprotein (a) (Lp[a]) concentrations and increased blood pressure. However, few studies have examined whether this association is present in subjects with non-insulin-dependent diabetes mellitus (NIDDM). We measured lipids, lipoproteins, Lp(a), blood pressure, and albumin excretion in 234 subjects with NIDDM from the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease. Seventy-two subjects had microalbuminuria (> or = 30 mg/dl). These subjects had increased systolic and diastolic blood pressures and higher fasting glucose concentrations relative to subjects without microalbuminuria. However, there were no significant differences between subjects with and without microalbuminuria with respect to lipids, lipoproteins, Lp(a), self-reported myocardial infarction, obesity, or body fat distribution. Subjects with diabetic retinopathy had increased microalbuminuria. In multivariate analysis both glycemia and blood pressure continued to be significantly related to the presence of microalbuminuria. We conclude that NIDDM subjects with microalbuminuria have elevated blood pressure and more severe glycemia but do not have a significantly more atherogenic pattern of lipids, lipoproteins, or Lp(a) than subjects without microalbuminuria.

Plasma lipoprotein (a) concentration and phenotypes in diabetes mellitus

Patients with Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent) diabetes mellitus are at increased risk of developing atherosclerotic vascular diseases. A variety of lipoprotein abnormalities have been described as being associated with this increased risk. In this study, apo(a) isoform frequencies and lipoprotein(a) [Lp(a)] concentrations were determined in Type 1 and Type 2 diabetic patients in order to investigate a possible contribution of Lp(a) to the increased risk for atherosclerosis in diabetes. No significant differences in plasma Lp(a) concentrations were found in two ethnically different populations (Austrians from the province of Tyrol and Hungarians from Budapest) in either type of diabetes when compared to respective control groups (91 Type 1 and 112 Type 2 diabetic patients vs 202 control subjects in the Hungarian study and 44 Type 1 diabetic and 44 Type 2 diabetic vs 125 control subjects in the Austrian study). There were also no significant apo(a) isoform frequency differences between both patient groups and control subjects in the two study groups. These data, obtained from two large ethnically different populations, provide no evidence of a contribution of Lp(a) to the increased risk for atherosclerosis in diabetes.

Microalbuminuria and other cardiovascular risk factors in nondiabetic subjects

The association between urinary albumin:creatinine ratio and other cardiovascular risk factors such as age, blood pressure, obesity, glycemic indices, insulin and lipid profile was examined in a population in a Chinese community consisting of 795 men (mean age 35.8 +/- 8.8 yr) and 538 women (mean age 37.9 +/- 8.9 yr) with a normal glucose tolerance defined by WHO criteria. Men with a urinary albumin:creatinine ratio above the 90th percentile had higher systolic and diastolic blood pressures, fasting plasma glucose, 2-h glucose after a 75 g oral glucose load, and fasting serum insulin. Women with high urinary albumin:creatinine values had higher systolic and diastolic blood pressures, body mass index, waist-hip ratio, fasting insulin and triglycerides. Multivariate analysis showed that only systolic blood pressure and fasting glucose in men, and diastolic blood pressure and fasting insulin in women, independently contributed to urinary albumin:creatinine. When the effect of blood pressure was eliminated by excluding subjects with systolic blood pressure > 140 and diastolic > 90 mm Hg, only fasting insulin was associated with urinary albumin:creatinine in women. No associations were found for men. We conclude that microalbuminuria may be a marker for cardiovascular disease only because of its association with blood pressure in men, while in women, there is an additional independent association with fasting serum insulin.

Plasma apolipoprotein (a) is increased in type 2 (non-insulin-dependent) diabetic patients with microalbuminuria

Patients with Type 2 (non-insulin-dependent) diabetes mellitus complicated by microalbuminuria or albuminuria, have an increased risk of developing macrovascular disease and of early mortality. Because lipoprotein abnormalities have been associated with diabetic nephropathy, this study tested the hypothesis that levels of apolipoprotein (a) are elevated in patients with Type 2 diabetes and increased levels of urinary albumin loss. Levels of apolipoprotein (a) in diabetic patients with microalbuminuria (n = 26, geometric mean 195 U/l, 95% confidence interval 117-324) and albuminuria (n = 19, 281 U/l, 165-479) were higher than in non-diabetic control subjects (n = 140, 107 U/l, 85-134, p < 0.05), and in the albuminuric group than diabetic patients without urinary albumin loss (n = 58, 114 U/l, 76-169, p < 0.05). Patients with microalbuminuria and albuminuria had levels comparable with patients undergoing elective coronary artery graft surgery (n = 40, 193 U/l, 126-298). Apolipoprotein (a) levels were higher in diabetic patients with macrovascular disease than in those without (n = 49, 209 U/l, 143-306 vs n = 54, 116 U/l, 78-173, p < 0.05). These preliminary results suggest that raised apolipoprotein (a) levels of Type 2 diabetic patients with microalbuminuria and albuminuria may contribute to their propensity to macrovascular disease and early mortality.

Apolipoprotein(a) in insulin-dependent diabetic patients with and without diabetic nephropathy

Insulin-dependent diabetic patients with diabetic nephropathy have a highly increased morbidity and mortality from cardiovascular diseases. To determine whether altered levels of apolipoprotein(a) (apo(a)), the glycoprotein of the potentially atherogenic lipoprotein(a) (Lp(a)), contribute to the increased risk of ischaemic heart disease, apo(a) was determined in 50 insulin-dependent diabetic patients with diabetic nephropathy (group 1), in 50 insulin-dependent diabetic patients with microalbuminuria (group 2), in 50 insulin-dependent diabetic patients with normoalbuminuria (group 3), and in 50 healthy subjects (group 4). The groups were matched with regard to sex, age and body mass index. The diabetic groups were also matched with regard to diabetes duration. The level of apo(a) was approximately the same in the four groups, being: 122 (x/ divided by 4.2) U l-1, 63 (x/ divided by 4.4) U l-1, 128 (x/ divided by 3.5) U l-1 and 126 (x/ divided by 3.7) U l-1 (geometric mean (x/ divided by antilog SD)) in group 1, 2, 3 and 4, respectively. 1 U l-1 apo(a) approximates 0.7 mg l-1 Lp(a).(ABSTRACT TRUNCATED AT 250 WORDS)

Lipoprotein(a) concentration in diabetes: relationship to proteinuria and diabetes control

Diabetic patients are at increased risk of cardiovascular disease, particularly when proteinuria is present. Lipoprotein(a)[Lp(a)] levels were assessed in 37 patients with insulin dependent (IDDM) and in 75 patients with non-insulin dependent (NIDDM) diabetes who showed varying degrees of proteinuria and glycaemic control. Median Lp(a) in 112 diabetic patients was significantly greater than in 116 healthy controls (113 vs 48 mg/L; p less than 0.01). 86 of the patients had first morning urine albumin concentration less than 30 mg/L (normoalbuminuria = NA), 16 patients 30-200 mg/L (microalbuminuria = MA) and ten patients greater than 200 mg/L (albuminuria = ALB). There was no significant difference in median Lp(a) concentration between the three groups (NA = 108, MA = 163, ALB = 98 mg/L; p greater than 0.5). No significant difference in median Lp(a) or NIDDM treated with oral agents and/or diet (120, 98, 115 mg/L respectively; p greater than 0.7). When the 86 NA patients were divided on the basis of median fructosamine concentration (357 mumol/L), no significant difference was found in median Lp(a) levels between those grouped below or above this median (98 mg/L vs 118 mg/L; p greater than 0.5). Across all diabetics studied there was no significant correlation present between Lp(a) and urinary protein or glycaemic control. These cross-sectional results suggest that median Lp(a) concentration is increased in both IDDM and NIDDM patients, but this increase is not related to the degree of proteinuria or short-term glycaemic control.