Association between glycaemic control and serum lipids profile in type 2 diabetic patients: HbA1c predicts dyslipidaemia.

Impaired lipid metabolism resulting from uncontrolled hyperglycaemia has been implicated in cardiovascular complications in diabetes patients. The aim of this study was to examine the impact of glycaemic control on the lipid profile of diabetic patients. We also determined the ability of glycated haemoglobin (HbA(1c)) as an indirect marker of dyslipidaemia. A total of 1011 type 2 diabetic patients (males, 574; females, 437; mean age, 59.76 years) were included in this study. Venous blood samples were collected from all the subjects after at least 8 h fasting. The sera were analysed for HbA(1c), fasting blood glucose (FBG), total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol (HDL) and low-density lipoprotein cholesterol (LDL). The levels of HbA(1c), FBG and LDL did not differ significantly between males and females. Female patients showed significantly higher serum cholesterol and HDL but significantly lower TG levels as compared to males. There was a highly significant correlation between HbA(1c) and FBG. Both HbA(1c) and FBG exhibited direct correlations with cholesterol, TG and LDL and inverse correlation with HDL; the magnitude of significance for all these lipid parameters being greater with HbA(1c) than FBG. There was a linear relationship between HbA(1c) and dyslipidaemia. The levels of serum cholesterol and TG were significantly higher and of HDL significantly lower in patients with worse glycaemic control as compared to patients with good glycaemic control. The findings of this study clearly indicate that HbA(1c) is not only a useful biomarker of long-term glycaemic control but also a good predictor of lipid profile. Thus, monitoring of glycaemic control using HbA(1c) could have additional benefits of identifying diabetic patients who are at a greater risk of cardiovascular complications.

Fluctuations in fasting blood glucose and serum fructosamine in pregnant women monitored on successive antenatal visits.

Fasting blood glucose (FBG) and serum fructosamine are simple and commonly used tests for monitoring diabetes mellitus. Unfortunately, both these parameters are associated with high error rates and therefore used with caution in high-risk populations. Setting high cut-off values for these parameters increases the sensitivity but at the cost of poor specificity (more false positives). Continued efforts have been made to evaluate the efficacy of FBG and fructosamine, singly or in combination, in avoiding a large number of unnecessary oral glucose tolerance tests (OGTT). Therefore, to better understand their time-course trends, we analysed FBG and c-fructosamine in 211 blood samples from 51 Saudi pregnant women during their multiple (> or =3) antenatal visits. The mean+/-standard deviation of FBG and c-fructosamine were 5.22+/-1.07 and 2.22+/-0.25 mmol/l respectively with a significant correlation between their individual values. Using the FBG cut-off >5.3 mmol/l, 19 subjects were classified as hyperglycaemic; this frequency was reduced to 1 when a FBG cut-off of >7.0 mmol/l was used. Combined values of FBG (>5.3 mmol/l) and c-fructosamine (>2.5 mmol/l) filtered 6 high-risk subjects with a prediction of gestational diabetes mellitus (GDM). Analysis of variance revealed high within-group variance for FBG. These fluctuations were also confirmed by higher coefficient of variations (CVs) for FBG (13.27%) as compared to c-fructosamine (5.49%). The CVs of FBG were not correlated with those of corresponding CVs of c-fructosamine (R = 0.007, P = 0.962), indicating that the fluctuations in FBG were independent of fluctuations in c-fructosamine. These findings clearly suggest that the paired values of FBG and c-fructosamine would be more advantageous than their individual values in filtering high-risk patients on whom OGTT should be performed.

Minor myocardial injury after elective uncomplicated successful PTCA with or without stenting: detection by cardiac troponins.

Cardiac troponins are sensitive and specific markers for the detection of minor myocardial injury. However, they have been rarely used to monitor myocardial injury after coronary stenting. The purpose of the study was to measure cardiac troponin I (cTnI) and cardiac troponin T (cTnT) levels after elective uncomplicated successful percutaneous transluminal coronary angioplasty (PTCA) with or without coronary stenting and to compare their results with serum creatinine kinase MB isoenzyme (CKMB). CTnI and cTnT levels were compared with those of CK or CKMB in 98 consecutive patients with stable angina undergoing elective uncomplicated successful PTCA with stenting (n = 71) or without stenting (n = 27). Markers were measured before and 6, 12, 24, and 48 hr after the procedure. Peak postprocedural levels for each marker were compared and related to angiographic and procedural characteristics as well as to the occurrence of side-branch occlusion. None of the patients had abnormal markers before the procedure. Abnormal postprocedural values of one or more markers were observed in 28 patients (29%), 23 after stenting and 5 after PTCA alone. The frequencies of abnormal cTnI and cTnT levels were significantly higher than that of CKMB after coronary intervention (26% and 18% vs. 7%; P = 0.00016 and 0.015, respectively), with cTnI being the most significant. When compared with troponin-negative patients, abnormal cardiac troponin values were significantly related to total time of inflation (223 +/- 128 vs. 170 +/- 105 sec; P = 0.008) and inflation maximal pressure (12.9 +/- 2.3 vs. 12.0 +/- 2.7 atm; P = 0.04). Small side-branch occlusion was noticed in 36% of the troponin-positive patients and in 6% of the troponin-negative group (P = 0.00047). In conclusion, minor myocardial injury is not uncommon after elective uncomplicated successful PTCA with or without stenting. Cardiac troponins, especially cTnI, are more sensitive than CKMB for the detection of this minor myocardial injury. Total time of inflation and inflation maximal pressure are predictors of postprocedural elevation of cardiac troponins. Side-branch occlusion may account for some, but not all, periprocedural minor myocardial injury.

Serum calcitonin in renal transplant patients.

We obtained blood samples from 60 renal transplant patients from our transplant clinic and from control subjects for biochemical analyses. Cyclosporin levels were measured in whole blood. Serum levels of calcitonin, calcium, phosphate, albumin, urea, creatinine, and activity of alkaline phosphatase were determined. Serum calcitonin levels were significantly higher in renal transplant patients. There was no correlation between serum calcitonin levels and activity of serum alkaline phosphatase, or levels of serum calcium, phosphate, albumin, urea, creatinine or cyclosporin. Serum calcitonin also showed no correlation with patient age or transplant age.

Changes in serum concentrations of markers of myocardial injury following treadmill exercise testing in patients with suspected ischaemic heart disease.

BACKGROUND: The treadmill exercise test (TEST) is frequently used in patients with suspected ischaemic heart disease to establish a diagnosis and estimate future risk. However, its predictive value is poor. We aimed to investigate whether measurement of biochemical markers of myocardial injury could improve the diagnostic value of the procedure. MATERIAL AND METHODS: Twenty-four subjects with suspected acute coronary syndrome underwent a treadmill exercise stress test. Of these 13 had had a previous myocardial infarction and two had a past history of coronary artery bypass grafting. Nine subjects were found to be positive for coronary ischaemia during the treadmill test. Serum cardiac markers (total creatine kinase [CK], CK-MB, Troponin I and Troponin T) were measured pre-TEST, and 0, 1, 2, 4, 8 and 24 hours following the treadmill test. RESULTS: Total CK remained within the reference range for all subjects and showed no significant rise. However, mean serum concentrations of CK-MB were significantly higher than pre-test values at 2 hours (p < 0.03) following treadmill exercise testing in subjects who had a positive exercise stress test, but not in those with a negative test. In the subjects with a positive stress test, CK-MB levels returned to pre-Test value by 24 hours. Levels of neither serum troponin I, nor troponin T altered significantly at any point. CONCLUSION: The measurement of CK-MB, but not cardiac troponins may add to the diagnostic utility of the TEST.

Cardiac markers used in the detection of myocardial injury.

OBJECTIVE: Activities of total creatine kinase and its isoform creatine kinase are usually significantly elevated in patients with myocardial or skeletal muscle injury as well as in those with renal failure. The purpose of this study was to compare findings for creatine kinase mass, cardiac troponin T and cardiac troponin I with those of creatine kinase and creatine kinase MB activity. METHODS: Blood samples from 118 patients were studied. Fifty eight patients had significantly elevated creatine kinase activity (39 with and 19 without clinically proven myocardial injury or infarction) and 60 were normal controls. The sensitivity, specificity, positive and negative predictive values were calculated for all markers. RESULTS: Cardiac troponins had 100% sensitivity and negative predictive value, for myocardial injury, as compared with 92% and 96% for creatine kinase activity and 96% and 97% for creatine kinase-mass. Cardiac TnI had the highest specificity and positive predictive value (99% and 98%) as compared with cardiac troponin T (96% and 93%), creatine kinase-mass (92% and 86%) and creatine kinase activity (89% and 80%). CONCLUSION: Cardiac troponins, especially cardiac troponin T, have very high sensitivity, specificity and predictive value for myocardial injury.

Thyroid function in cord blood.

OBJECTIVE: To determine the biochemical parameters of thyroid function in the cord blood of Saudi infants. METHODS: Cord blood samples sent to the Pathology Department for screening for congenital hypothyroidism were used to determine the reference ranges for thyrotropin, free thyroxine, free triiodothyronine, thyroxine-binding globulin and thyroglobulin. All the measurements were carried out by immunoassay (Elisa, microparticle enzyme immunoassay or chemiluminescence immunoassay). Reference ranges were calculated after exclusion of outliers. RESULTS: Reference ranges for thyrotropin, free thyroxine and thyroxine-binding globulin were similar to published values, whereas those for free triiodothyronine and thyroglobulin were different. CONCLUSION: For correct interpretation of the parameters of thyroid function in cord blood it is essential to have reference ranges based on the laboratory's current methods and derived from the local population.

Detection of minor myocardial injury after successful percutaneous transluminal coronary angioplasty with or without stenting.

Cardiac troponins are sensitive and specific markers for the detection of minor myocardial injury. However, they have been rarely used to monitor myocardial injury after coronary stenting. The purpose of the study was to measure cardiac troponin I (cTnI) and cardiac troponin T (cTnT) levels after apparently successful percutaneous transluminal coronary angioplasty (PTCA) with or without coronary stenting and to compare their results with serum creatine kinase (CK) and its isoform, creatine kinase-MB (CKMB). CTnI and cTnT levels were compared with those of CK or CKMB in 50 consecutive patients with stable angina undergoing visually successful PTCA with stenting (n = 35) or without stenting (n = 15). Cardiac TnI, cTnT, CK and CKMB levels were measured before and 6, 24, and 48 hours after the procedures was performed. None of the patients had abnormal cTnI or cTnT levels, CK activity, or CKMB levels before the procedures. Moreover, no patient showed electrocardiographic evidence of myocardial infarction. 13 patients (26%) had abnormal peak values of one or more markers at 24 hours after coronary intervention. Troponin I was elevated in 10/35 patients after coronary stenting (29%) and in 2/15 patients after PTCA (13%) (P = 0.327). Troponin T was elevated in 6 patients (17%) and CKMB activity was elevated in 3 patients (9%) of the coronary stenting group. CTnI was more significant than CKMB (P = 0.023) in detecting minor myocardial injury. When compared with cTnI and CKMB, cTnT did not reach significance (P = 0.129 and 0.489, respectively). 5 out of the 13 patients with abnormal markers (38%) developed side branch occlusion after stenting. In conclusion, cTnI was a very sensitive marker in detecting minor myocardial injury after coronary angioplasty with or without stenting. The frequency of increased serum levels of cardiac troponins was higher in patients undergoing stent implantation than in those treated with angioplasty alone but did not reach significance. Side branch occlusion may have accounted for some, but not all, periprocedural minor myocardial injury in the stent group.

Influence of sex and chronic haemodialysis treatment on total, free and acyl carnitine concentrations in human serum.

The influence of sex and haemodialysis treatment on serum total, free and acyl carnitine concentrations in healthy controls and chronic renal failure patients has been investigated. Patients on regular haemodialysis treatment generally displayed significantly decreased serum carnitine levels. The mean predialysis serum carnitine levels were not significantly different from the mean healthy control values. However, after dialysis a significant decrease in serum carnitine levels was observed compared to the predialysis and healthy control values. Moreover, serum ratio of acylated to free carnitine was significantly higher after haemodialysis as compared to both healthy controls and predialysis patients. Sex-related changes in serum total, free and acyl carnitine levels and ratios of acylated to free carnitine have been observed in healthy controls and patients on chronic haemodialysis treatment.

Hearing impairment in association with distal renal tubular acidosis among Saudi children.

A follow-up of seven patients with the autosomal recessive inherited syndrome of distal renal tubular acidosis (RTA) and sensorineural hearing loss is described. Five patients were diagnosed as having primary distal renal tubular acidosis and rickets, four were found to have severe sensorineural hearing loss of over 80 dB: two of which are brothers. Two patients were diagnosed as having secondary distal renal acidosis due to a genetic disorder called osteopetrosis; they are brothers and their audiograms showed a mild conductive hearing loss of an average 35 dB bilaterally. All patients had growth retardation with improvement due to alkaline therapy but their hearing loss was not affected by the medication. The pedigrees of two families with half sibs showed the familial incidence for consanguineous marriage. Consanguinity was found to be positive in five out of the seven patients. The tribal tradition in Saudi Arabia fosters consanguineous marriages for cultural and social reasons and pre-arranged marriages are still seen.