Increased high density lipoproteins in diabetic children

Angiotensin-converting enzyme gene polymorphism and lipid profiles in Kuwaiti children with type 1 diabetes

METHODS

We studied angiotensin-converting enzyme (ACE) gene polymorphism and lipid profiles in Kuwaiti children with uncomplicated type 1 diabetes. A total of 125 children with type 1 diabetes were matched in a case-control study on age and gender to 125 non-diabetic children as controls. Serum lipids (total cholesterol, TC; high-density lipoprotein cholesterol, HDL; low-density lipoprotein cholesterol, LDL-c; triglycerides, TG; apolipoprotein A1 and B, apo A1 and B; lipoprotein(a), Lp(a)); and glycated hemoglobin, HbA1c were evaluated according to ACE genotypes.

RESULTS

Genotype distributions were found to be similar in cases [ACE insertion/insertion (II) 9.6%, ACE insertion/deletion (ID) 38.4%, ACE deletion/deletion (DD) 52.0%], and controls (II 8.8%, ID 43.2%, DD 48.0%), and were characterized by higher frequencies of DD, ID, and lower frequencies of II. Diabetic children with DD genotype showed significantly higher levels of TC (p < 0.01), HDL (p < 0.001), and apo A1 (p < 0.001) than controls. There was a higher proportion of diabetic children with family history of cardiovascular disease (CVD) in the DD genotype group (51.9%) than those with II genotype group (11.1%) (p < 0.001). Also, there was a significant increase in the frequency of diabetic children with Lp(a) > 30 mg/dL in children with a family history of CVD (p = 0.008). Lp(a) levels were correlated with HbA1c in the diabetic group (r = 0.239, p = 0.019), but when patients with poor glycemic control (HbA1c > 9%) were excluded, the significant correlation disappeared (r = 0.127, p = 0.381). After adjusting confounding between variables, the logistic regression analysis showed that the two significantly related variables with the rise in Lp(a) were increasing TC level and poor glycemic control.

CONCLUSIONS

In children with type 1 diabetes, the role of ACE polymorphism as a probable contributor to CVD seems to be partially mediated through other factors such as poor glycemic control, TC, and Lp(a) level. A longitudinal study is recommended with a larger number of patients in each ACE genotype group in order to assess such associations.

Glycemic control, oxidative stress, and lipid profile in children with type 1 diabetes mellitus

BACKGROUND

In diabetes mellitus, persistence of hyperglycemia was reported to cause increased production of oxidative parameters including malondialdehyde (MDA). In the present study, the effect of glycemic control on oxidative stress and the lipid profile of pediatric type 1 diabetes mellitus (DM) patients were investigated.

METHODS

Serum total cholesterol, HDL cholesterol, VLDL cholesterol, apolipoprotein A, apolipoprotein B, lipoprotein a, HbA(1c), and MDA levels were assessed in 96 children with type 1 DM. Study cases were evaluated in two groups in view of their mean HbA(1c) values, as metabolically well controlled (HbA(1c) < or =8%) and poorly controlled (HbA(1c) >8%) patients with DM. Fifty healthy children were included as normal controls.

RESULTS

Total cholesterol, LDL cholesterol, apolipoprotein A, apolipoprotein B, and MDA levels of total diabetic patients were significantly (p<0.05) higher than those of the control group. Serum MDA levels and MDA/LDL cholesterol index were significantly increased in metabolically poorly controlled in relation to metabolically well-controlled DM patients and were similar in metabolically well-controlled DM patients with relation to control group and in metabolically poorly controlled patients with relation to control group.

CONCLUSIONS

In the present study, increased levels of MDA, MDA/LDL index, and dyslipoproteinemia showed that especially metabolically poorly controlled DM children are at high risk of atherosclerosis and vascular complications of DM and that there is a significant relationship between the lipid profile and oxidative stress. Thus, it may be appropriate to evaluate MDA in addition to routine laboratory assessments in evaluation of type 1 DM pediatric patients.

Glycaemic control and familial factors determine hyperlipidaemia in early childhood diabetes. Oxford Regional Prospective Study of Childhood Diabetes

AIMS

To determine whether abnormal lipid levels in children with Type 1 diabetes mellitus are the result of poor metabolic control or may in part be determined by genetic factors.

METHODS

Non-fasting lipid levels were measured in 141 children with Type 1 diabetes (age range 7.7-19 years) 3 years after diagnosis, and in 192 of their parents. Glycosylated haemoglobin and the urinary albumin-creatinine ratio (three urine samples) were estimated in each child annually.

RESULTS

The children had a mean total cholesterol of 4.46 +/- 1.25 mmol/l (+/- SD) and a median triacylglycerol of 1.18 mmol/l (range 0.32-4.7). A total of 15.3% of the population had a total cholesterol > 5.2 mmol/l and 17.9% had a triacylglycerol > 1.7 mmol/l; in 5.6% both total cholesterol and triacylglycerol were greater than these cut-off points. Total cholesterol, triacylglycerol and very low density lipoprotein-cholesterol were significantly correlated to glycaemic control. However, total cholesterol was also significantly related to parental total cholesterol either as analysed separately or as mean parental total cholesterol (r = 0.37, P = 0.0001). In stepwise multiple regression analysis both mean parental total cholesterol (P = 0.001) and HbA1c (P = 0.015) were significant determinants of the child's total cholesterol. The children studied were being followed prospectively for the development of microalbuminuria and there was a weak association across tertiles of total cholesterol, linking higher levels to the development of microalbuminuria (P < 0.05).

CONCLUSIONS

We conclude that both glycaemic control and familial factors may be important determinants of lipid levels in young people with diabetes. Both may contribute to the subsequent risk of cardiovascular disease and possibly the development of incipient diabetic nephropathy.

Serum lipoproteins and apolipoproteins in children during the first five years of diabetes

Serum lipoproteins and apolipoproteins were followed in 34 children during a period of 5 years from the onset of diabetes. The group did not differ in these respects from a healthy control group after 5 years of disease. The variation in serum triglycerides and very-low-density lipoprotein (VLDL) triglycerides was more pronounced, some patients having high values. Serum triglycerides and VLDL lipids were significantly correlated to subcutaneous fat, measured as triceps and subscapular skinfolds. None of the patients had albuminuria, so lipid levels could not be related to renal albumin excretion. There was no significant correlation between any serum lipid and haemoglobin A1c.

Circulating lipids and glycaemic control in insulin dependent diabetic children

The prevalence of dyslipidaemia in children with insulin dependent diabetes mellitus (IDDM) and its relation to glycaemic control was studied in a group of 51 diabetic children and a control population of 132 schoolchildren. The prevalence of dyslipidaemia in the fasting state was increased in the diabetic group (39%) compared with control subjects (17%). Serum cholesterol concentration alone was raised in 25% of diabetic subjects while serum cholesterol and triglycerides were raised in 14%, compared with 16% and 0.7% respectively in control subjects. Serum total cholesterol (5.1 v 4.5 mmol/l), low density lipoprotein cholesterol (3.2 v 2.6 mmol/l), non-esterified fatty acids (0.91 v 0.50 mmol/l), and triglycerides (0.94 v 0.76 mmol/l) were higher in diabetic children. Serum total cholesterol, triglycerides, and apolipoprotein (apo)B concentrations increased with worsening control, while serum high density lipoprotein cholesterol and apoA-I concentrations were unaltered. There were also positive correlations between glycated haemoglobin and total cholesterol, triglycerides, and apoB in diabetic children. Thus, abnormalities in circulating lipids are common in young subjects with IDDM but largely disappear if blood glucose concentrations are reasonably controlled.

The influence of dietary education in diabetic children

The aim of our study was to evaluate the efficacy of dietary education in inducing modification of the diet and to measure biochemical parameters in 36 children and adolescents with IDDM. At the beginning of the study, each patient was evaluated as follows: food intake (by the method of the 24-h recall for 3 days), auxological parameters, biochemical parameters. Thereafter a program of nutritional guidelines was provided. Subsequent meetings took place at 1-month-intervals. The study ended 3 months later, when all the parameters were completely revalued. We observed improved nutrition in our patients both in terms of total caloric intake and calorie distribution. In particular there was an increase in carbohydrates and a reduction in lipids, reaching the percentage levels recently recommended. With a reduction in lipid intake a significant decrease in LDL cholesterol and a significant increase in HDL cholesterol were noticed in our patients. These modifications are very important for the prevention of arteriosclerosis and thus macrovascular disease. We maintain that dietary education plays an important role in helping children and adolescents with IDDM to follow a suitable diet.

Serum lipids and apolipoproteins in children with type 1 (insulin-dependent) diabetes during the first two years of the disease

Serum lipoproteins and apolipoproteins were studied at diagnosis and 6, 12 and 24 months later in 30 consecutive children aged 3-15 years with newly detected Type 1 (insulin-dependent) diabetes mellitus (December 1982-October 1984) and in 44 healthy control children. Serum triglycerides at diagnosis were significantly higher than after 6-24 months and also higher than in the control group (p less than 0.001). At follow-up, triglycerides in the very low density lipoproteins and low density lipoproteins were restored to normal, while high density lipoprotein triglycerides remained high. Serum cholesterol at onset of diabetes was significantly higher than in the control children (p less than 0.01), mainly because of increased very low density lipoprotein cholesterol (p less than 0.001). Cholesterol in serum and in the serum lipoprotein fractions was similar to that in the control children at follow-up, except that high density lipoprotein cholesterol was higher in the diabetic children after 6 months. The concentrations of the serum apolipoproteins A-I, A-II and B were higher at onset of diabetes than in the control children (p less than 0.001, p less than 0.01, p less than 0.05 respectively), with a significantly increased ratio of apolipoprotein A-I to A-II in the diabetic children (p less than 0.001). The serum apolipoprotein concentrations were normalised during treatment. The ratio of apolipoprotein A-I to B did not differ from that in control children. On admission, there were strong positive correlations between HbA1c and the concentrations of the very low density lipoproteins and the low density and high density lipoprotein triglycerides.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum selenium is related to low-density lipoproteins in healthy children but not in children with diabetes

The serum concentrations of selenium in 13 healthy children and 27 children with type 1 diabetes mellitus were evaluated in relation to serum lipoprotein and apolipoprotein concentrations. In healthy children a correlation was found between serum selenium and both serum cholesterol (r = 0.56; p less than 0.05) and serum triglycerides (r = 0.56; less than 0.05) and their low-density lipoprotein (LDL) + very low-density lipoprotein (VLDL) fractions (r = 0.60 and 0.56 respectively; p less than 0.05), but not their high-density lipoprotein fractions. Associations were also found between selenium and apolipoproteins, especially A II and C II (r = 0.57; p less than 0.05). In diabetic children serum selenium was significantly correlated with apolipoproteins A II and Apo C II, but not with any lipoprotein or lipid or any of their fractions. This study supports the hypothesis that serum selenium is an integral part of the defence system against degradation products associated with LDL and VLDL in young healthy humans. These associations were not found in diabetes, which might suggest that the defence system against lipid peroxidation is less effective in this disease.

The metabolic and hormonal effects of continuous subcutaneous insulin infusion therapy in diabetic children

To find out whether the concurrent metabolic and hormonal abnormalities are corrected when normoglycaemia is achieved, two groups of diabetic children (newly-diagnosed and chronically-treated) were treated with insulin pumps. Fasting levels of metabolites, lipids and hormones were measured before and after 8 to 10 days of pump treatment and the immediate postprandial hormonal and metabolic changes after a test-meal were also measured. Restoration of normoglycaemia was accompanied by correction of multiple metabolic abnormalities including the normalisation of fasting plasma free insulin, growth hormone, free fatty acid, triglyceride and total cholesterol levels. Plasma glucagon, however, decreased below normal, and significant hypoketonaemia developed in newly-diagnosed diabetic children. The fall in (VLDL + LDL)-cholesterol levels was accompanied by a substantial increase in HDL2-cholesterol concentration in newly-diagnosed diabetic children, whereas pump-treatment resulted in a decrease of the HDL3-cholesterol subfraction in chronically-treated diabetic children. The postprandial blood glucose and free insulin profiles were similar to that of control subjects, but there was an "abnormal" postmeal fall in plasma glucagon and free fatty acid levels. These changes together with the fasting hypoglucagonaemia and hypoketonaemia indirectly suggest that optimal glycaemic control is only achievable at the expense of "increased insulin action" despite the failure to detect peripheral hyperinsulinaemia. Furthermore, the restoration of normoglycaemia and the simultaneous normalisation of the metabolic and endocrine milieu is not entirely possible with this mode of therapy.

Type 1 (insulin-dependent) versus type 2 (non-insulin-dependent) diabetes mellitus: characterization of serum lipoprotein alterations

Serum lipoprotein lipids and apolipoproteins A-I, B, and E were investigated in Type 1 (insulin-dependent) diabetics, Type 2 (non-insulin-dependent) diabetics, and two control groups, twenty subjects each. Lipoproteins were separated and analysed by common methods, apolipoproteins were measured by endpoint immunonephelometry. Compared with controls, Type 2 diabetics had increased serum apolipoprotein E levels (0.116 +/- 0.020 vs. 0.079 +/- 0.014 g 1-1, P less than 0.01) together with an increased content of cholesteryl ester-enriched very low-density lipoproteins. Furthermore, Type 2 diabetics had higher apolipoprotein B concentrations (1.06 +/- 0.21 vs. 0.85 +/- 0.21 g l-1 P less than 0.01), but lower high-density lipoprotein cholesterol concentrations than the controls. Conversely, Type 1 diabetics had elevated serum apolipoprotein A-I values vs. controls and Type 2 diabetics (1.70 +/- 0.33 vs. 1.49 +/- 0.22 and 1.43 +/- 0.21 g 1-1, P less than 0.01). It is concluded that Type 2 diabetics, like other groups at risk for atherosclerotic diseases, are characterized by an increased concentration of partly catabolized very low-density lipoproteins. Sufficiently insulinized Type 1 diabetics have, on the other hand, an increased number of high-density lipoprotein particles.

Effect of diabetes mellitus and end-stage renal disease on HDL metabolism

Different types of diabetes mellitus have different effects on high density lipoprotein (HDL) metabolism. Impaired glucose tolerance may be associated with no change or a slight decrease in HDL cholesterol. Type I diabetes may have normal or elevated HDL cholesterol levels. This HDL elevation may be due to an increase in HDL2 or HDL3. Apo A-I/Apo A-II ratio is also higher in these diabetics. Type II diabetics may have normal or low HDL cholesterol levels as well as normal or decreased Apo A-I levels. In gestational diabetics, the mean HDL cholesterol is lower than controls. Dietary therapy resulting in greater than 10% weight loss in obese diabetics leads to an increase in their HDL-cholesterol levels, although the effect on the latter is controversial. Intensive insulin therapy (for 2-3 weeks) increases serum apo A-I and HDL-cholesterol levels. End-stage renal disease also affects HDL metabolism. In general, patients with this disorder have a decrease of cholesterol and an increase in triglyceride in their HDL. There is an increase in apo E and a decrease in apo CII in their HDL. Apo A-I levels are unaffected whereas apo A-II levels are decreased. Renal transplant patients may have low, normal or high HDL cholesterol and normal or high apo-I levels. In non-diabetic, normotriglyceridemic patients peritoneal dialysis increases their HDL-cholesterol. In non-diabetic hypertriglyceridemic and diabetic patients, peritoneal dialysis causes no change in their HDL-cholesterol.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoproteins and lipoproteins in children with type I diabetes: relation to glycosylated serum protein and HbA1

Serum levels of cholesterol (C), triglycerides (TG), lipoprotein-C and apolipoproteins (apo) A-I, A-II and B were measured in 30 children with type I diabetes mellitus (16 boys, 14 girls, aged 11-14 years) and in 26 healthy controls (15 boys, 11 girls, aged 10-13 years). For 19 diabetics controls matched for age, sex and relative body weight were selected. The diabetic patients were considered to be in fair metabolic control according to HbA1 levels and glycosylated serum protein concentrations. Mean serum apo A-I, A-II and B, C, TG, low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) did not differ significantly between diabetic nondiabetic children. Very low density lipoprotein cholesterol (VLDL-C) was significantly higher in diabetic children than in controls. Serum C and LDL-C levels showed close univariate linear correlations with glycosylated serum protein (LDL-C: r = 0.53, p less than 0.01, C: r = 0.58, p less than 0.01) in diabetics. The ratio LDL/HDL-C was significantly correlated to HbA1 levels (r = 0.47, p less than 0.01). By canonical and multiple linear correlation analysis significant relations of a selected set of variables concerning the control and therapy of diabetes (serum glucose, HbA1, glycosylated serum protein, insulin dose) with a set of lipoprotein variables (C, TG, VLDL-C, HDL-C, LDL-C, apo A-I, A-II, B) could be demonstrated. From these data we conclude that significant relations between atherogenic serum lipids and lipoproteins (C, LDL-C) and the degree of metabolic control exist in diabetic children, even in the absence of marked dyslipoproteinemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary intake in Swedish diabetic children

The energy and nutrient intakes by 14 children with type I diabetes and 13 healthy peers were investigated by the 24-h recall method and the results were compared with current recommendations for the general population and with the guidelines for the dietary management of diabetes mellitus. The diabetic children showed not only good compliance with the recommendations but also a better intake in practically all respects than their healthy counterparts. The total energy intake by the diabetic children was in good agreement with the recommendations, while that of the controls was slightly lower. The protein energy per cent in the diet of the diabetic children was 18%, compared with 14% in the controls. Forty percent of the energy in the diet of the diabetic children was derived from fats, 36% in the controls. With the exception of carbohydrates, ascorbic acid and iron, the diet of the diabetic children had a higher nutrient density than that of the control children and the reverse was true for carbohydrates only. However, because of the generally higher energy intake displayed by the diabetic children, even the intake of these nutrients was at least as good in the diabetic children as in the controls. Eighty-six percent of the diabetic children but only 46% of the control children stated that the day for which intake data were given was a representative day.