Interpreting HbA1c in Presence of Deficiency Anemias.

HbA1c is used extensively for the diagnosis and management of diabetes mellitus. It constitutes 80% of glycated HbA1(Glycated haemoglobin(GHb)A), and depends upon blood glucose and RBC life span. RBC life span varies with anemia, leading to a consequent alteration in the HbA1c value irrespective of the circulating blood glucose concentration. But to the best of our knowledge no Hb cut offs have been derived for appropriate interpretation of HbA1c. The prevalence of anemia in Indian population is nearly 40% as per its definition by WHO-Hb < 12 g/dL in females and < 13 g/dL in males-with most cases attributable to nutritional deficiencies. Hence, we aimed to identify Hb cut-off for accurate interpretation of HbA1c in presence of deficiency anemias. Partial correlation between random blood glucose (RBG) and HbA1c was studied in 1312 subjects, 470 of whom had deficiency-related anemia]. The data was adjusted for age, sex and Hb. Partial correlation between RBG and HbA1c was highly significant (p < 0.0001) till Hb of 8.1 gm/dL. Significance reduced to p = 0.003 and p = 0.006 as the cut off of Hb reduced to 7.1 gm/dL and 5.0 gm/dL, respectively, but was not lost. Hence, caution in interpretation of HbA1c is not required till an Hb of 5 g/dL.

The Hemolyzed Sample: To Analyse Or Not To Analyse.

Preanalytical errors constitute about 40-65% of laboratory errors, of which 60% are due to hemolysis. This leads to imprecise reporting and misinterpretation of the actual concentration of analytes. Hence the aim of this study was to estimate the extent of different degrees of interference by visible hemolysis. 25 hemolysed samples along with their fresh unhemolysed sample were studied. Hemolyzed serum was mixed with unhemolyzed serum in predefined serial ratios from 100%, 70%, 50%, 30% and 10% to achieve different grades of hemolysis. Each dilution was analysed for BUN, creatinine, uric acid, phosphorus, Na, K, total protein, amylase, lipase, LDH, tacrolimus and methotrexate. Percentage difference of each dilution of the hemolyzed sample as compared to the unhemolyzed sample was calculated and considered acceptable only if less than TEa. It was observed that Percentage difference of BUN, creatinine, amylase and lipase in all dilutions of hemolyzed samples were within TEa while phosphorus, Na, K, total protein and LDH were beyond the acceptance criteria. Hence It was concluded that it may be safe to analyse a hemolysed sample for BUN, creatinine, amylase, lipase, tacrolimus and methotrexate while uric acid may be estimated in a moderately hemolysed sample. Phosphorus, sodium, potassium, total protein and LDH must never be analyzed in any hemolysed sample.

Non-HDL as a Valid Surrogate Marker of Small Dense LDL in a Young Indian Population.

Small dense (sd) LDL is a significant independent risk factor for premature coronary artery disease (CAD). Unfortunately, its estimation is not popular, due to the limited availability of specialized equipment, high cost and time-consuming technique. Non-HDL is a calculated, single index measure of all atherogenic apolipoprotein-B containing lipoproteins. This study aimed at identifying non-HDL as a superior surrogate marker of sdLDL cholesterol in a young Indian population. 161 healthy subjects < 45 years were tested for lipid profile, apolipoproteins A1 and B, and sdLDL particle size. sdLDL particles showed negative correlation with non-HDL (r = - 0.283, p < 0.001), LDL (r = - 0.195, p = 0.013) and apoB/apo A1 (r = - 0.175, p = 0.026), the significance being greatest with non-HDL. ROC showed AUC for non-HDL, LDL and apoB/apo A1 as 0.704, 0.686, and 0.596 respectively. For LDL < 130 mg/dL, sdLDL showed a more significant negative correlation with non-HDL (r = - 0.291, p < 0.001) as compared with apoB/apoA1 (r = - 0.172, p = 0.037). For triglycerides < 200 mg/dL, sdLDL particle size showed higher significant negative correlation with non-HDL (r = - 0.213, p = 0.015) than with LDL (r = - 0.176, p = 0.045) while for triglycerides between 200 and 400 mg/dL, significant negative correlation was observed only with non-HDL (r = - 0.372, p = 0.043). Hence, our study suggested that non-HDL is a superior surrogate marker of sdLDL particle size as compared to LDL and apoB/A1 ratio in a young healthy Indian population and should be used for optimum assessment of dyslipidemias and CAD risk.

Free radical status in retinopathy of prematurity.

Retinopathy of prematurity (ROP) is a major cause of blindness in children. Free radicals are implicated in the development of this retinopathy. We studied the role of free radicals in ROP and enrolled 60 preterm neonates at 30-32 weeks age. Thirty neonates predisposed to development of ROP, were placed in study group and 30 normal neonates in control group. Malondialdehyde and antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX) were measured in blood spectrophotometrically. Both the groups were followed-up to 40-42 weeks age. Serum MDA levels, erythrocyte SOD and plasma GPX were significantly high in study group at 30-32 weeks as compared to control group. At follow up visit significant increase in MDA level and decrease in SOD and GPX level among the study group was seen. This disturbance in equilibrium of oxidant and antioxidant status initiates an inflammatory process in retinal tissue leading to development of ROP.

Preanalytical error occurrence rate in clinical chemistry laboratory of a public hospital in India.

BACKGROUND: The pre and post analytical phase in a testing cycle contributes up to 93% of total laboratory errors. Hence, it is of utter importance for the laboratory to study error occurrence rates during the testing cycle and implement a quality improvement plan to release an accurate result. METHODS: The present study was conducted during the period 2008 - 2009 in the clinical biochemistry lab in Lady Hardinge Medical College and associated hospitals. During a 6 month period 32,589 samples were monitored for major preanalytical problems at the receiving counter of the laboratory. RESULTS: Out of all laboratory problems, up to 61% are associated with the preanalytical phase in the lab. Out of this, 33% of the errors are associated with the test request forms, 18% errors with sample collection in glass vials, and 3% errors associated with sample processing in the laboratory. As per Quality Improvement policy of the lab, a closed blood evacuation system (vacutainers) has been implemented for sample collection. Post implementation, preanalytical error rate has been reduced to 48%, however, tube filling errors still remain the major problem noted. CONCLUSIONS: Based on these observations, transcription errors related to test request forms is of great concern and needs corrective measures via proper educational programs. If this area is compromised it can lead to adverse patient outcome. However, with the use of vacutainers a better specimen quality and health care worker safety is achieved. It also decreases inconvenience to the patient.

Metabolic effects of obesity: A review.

With the many recent advances in the biomedical world, vast changes are taking place in our growing knowledge of the physiological aspects of almost all the tissues and organs of the human body. One of the most prevalent topics of discussion is the question of obesity and its effect on the metabolic changes in the human body. The original classical role of adipose tissue as an energy storage organ has been greatly modified. We now know that it is an endocrine organ, producing adipokines like leptin, adiponectin, visfatin, resistin, apelin, etc, which modulate metabolic processes in the body. Since obesity is associated with an increase in the adipose tissue mass, these hormones may be expected to be produced in increased concentrations and may thus have a significant impact on the macronutrient metabolism. Further, these adipokines may interact with long term energy modulators like insulin. Even though the scientific community has started unravelling the mysteries of the close linkage between obesity, its hormones and their physiological effects, a lot still remains to be discovered. The present discussion makes an attempt to trace the basic modern day concepts of the role of obesity in various metabolic processes.