Glycated haemoglobin and other biochemical parameters in Sudanese diabetics

Vitamin A, retinol binding protein and lipids in type 1 diabetes mellitus

OBJECTIVE

A case-control study was conducted to evaluate the effects of type 1 diabetes mellitus (IDDM) on plasma levels of vitamin A (retinol) and serum levels of retinol-binding protein (RBP) and their relationship with the atherogenic indicators.

SUBJECTS

A total of 47 randomised IDDM children were recruited from those treated at the Endocrinology Unit of the University Hospital of Granada (Spain). They were matched for age and sex with 16 healthy children.

METHODS

The following parameters were measured in all patients: serum concentrations of total cholesterol, triglycerides, high (HDL, spectrophotometry), very low (VLDL) and low (LDL) density lipoprotein cholesterol (Friedewald's formula); serum levels of RBP (kinetic nephelometry); plasma vitamin A and glycosilated haemoglobin (HbA1c; high performance chromatography).

RESULTS

Higher RBP concentrations in IDDM children (P=0.05), lower retinol levels (P=0.05) and lower vitamin A/cholesterol ratio (P=0.02) than in the control group were found; no differences in the atherogenic indicators were observed. There was a correlation between RBP and vitamin A (P=0.0001). Relationships between retinol, RBP and atherogenic indicators were demonstrated in the IDDM group (A-LDLc/HDLc (P=0.01); A-(VLDL+LDL)c/HDLc (P=0.007); RBP-LDLc/HDLc (P=0.05); RBP-(VLDL+LDL)c/HDLc (P=0.02)), and an inverse relationship was found between the vitamin A/TG ratio and HbA1c (P=0.004). The children with HbA1c>8% showed increased atherogenic indicators and lower vitamin A/CHOL and vitamin A/TG ratios than those with good control of the illness.

CONCLUSIONS

The IDDM children with poor metabolic control face a higher atherogenic risk and vitamin A 'relative deficiency' risk than those with good metabolic control of their illness. Relationships between retinol and RBP with atherogenic indicators were found. The results suggest that vitamin A therapeutic supplements in IDDM children may reduce or prevent atherogenic risk.

Monitoring diabetic control in developing countries: a review of glycated haemoglobin and fructosamine assays

Measurement of glycated proteins, especially haemoglobins, is now a routine procedure for monitoring previous glycaemic control in diabetic patients in the developed world. Until recently, however, the assays were sophisticated and costly and, therefore, were only rarely used in developing countries. With easier and cheaper tests now available, the measurement of glycaemic control could be also introduced into regional hospitals in developing countries. This paper reviews feasible methods for clinical laboratories with limited resources. Recent experiences from African countries are included.

Glycaemic control and its determinants in diabetic patients in Ethiopia

A cross-sectional study was undertaken in which concentrations of glycated haemoglobins were measured in 102 diabetics seen at the outpatient clinic in Gondar, Ethiopia, between 26 January and 7 March, 1995. Mean HbA1, levels (standard deviations) were 5.35% (1.1) in non-diabetic controls, 12.0% (1.5) in 59 insulin-dependent diabetics, and 11.0% (2.0) in 43 non-insulin dependent outpatients. The majority of insulin-dependent mellitus (IDDM) (78%) and non-insulin-dependent mellitus (NIDDM) patients (77%) were poorly controlled (HbA1 > 10.8% in IDDM, and > 9.7% in NIDDM, respectively). Multiple linear regression analyses revealed that HbA1 levels were significantly positively associated with lower body mass index, duration of diabetes, a recent history of polydipsia, hypertension, and low income in NIDDM individuals. Whereas in IDDM patients lower age (or alternatively lower age at onset) was the only significant predictor. Whilst 49% of the model variance was explained by the predictors in NIDDM diabetics, only 9% were so in IDDM patients. Current fasting blood glucose level was marginally significant in NIDDM patients (r = 0.29; P = 0.058), but insignificant in IDDM individuals. This points towards the fluctuations in blood glucose levels experienced by IDDM patients in a setting where insulin supply is unreliable. It also confirms the doubts about the usefulness of fasting blood glucose values as a tool for assessing metabolic control.

Cord and maternal glycosylated haemoglobin levels: a study in Sudanese pregnant diabetic women

Blood glucose and glycosylated haemoglobin levels measured at delivery in 27 normal and 19 diabetic women were compared with those of the corresponding fetuses and their birthweights. In both groups, neonatal blood glucose levels were significantly higher (p much less than 0.001) than the maternal levels despite significantly lower (p much less than 0.001) glycosylated haemoglobin values in the neonates. In the control group, there was a significant correlation of maternal glycosylated haemoglobin with both cord glycosylated haemoglobin and birthweight ratio (p less than 0.01). The same was not obtained in the diabetic group, suggesting a dissociation in glucose homeostasis between the diabetic pregnant mother and her fetus.