A simple, cost-effective quality assurance model for measurement of lipids in a large epidemiological study.

BACKGROUND: Laboratory measurements are an integral part of epidemiological studies in cardiovascular disease. Standardization and quality assurance is of utmost importance in the context of multicentre studies. METHODS: We evaluated a simple and cost-effective method of quality assurance for measurement of total cholesterol, high density lipoprotein (HDL) cholesterol and triglycerides in a study involving 10 centres. Three methods for quality assessment were used for the study that involved measurement of cholesterol, triglycerides and HDL cholesterol and included internal quality control, external quality control and 10% repeat analysis in addition to a uniform standardized protocol developed for the 10 centres. External quality control material was prepared and circulated by the coordinating laboratory. RESULTS: External quality control material was distributed 20 times during the study. The mean variance index suggested a substantial improvement in the performance of participating laboratories over a period of time for cholesterol and triglycerides. This was also evident in the improvement in per cent technical error as a measure of bias and a higher correlation between replicates of samples analysed in the coordinating laboratory and the participating centres for cholesterol, triglycerides and HDL cholesterol. CONCLUSION: A cost-effective quality assurance model for laboratory measurement using local capacities was developed and implemented in a multicentre epidemiology study. Such a programme would be useful for developing countries where cost-cutting is important.

Role of prolactin in human milk composition and serum lipids studied during suppression of galactorrhea with bromocriptine.

Bromocriptine suppressed lactation by depressing the serum prolactin (PRL) level in 10 of 12 cases with profuse galactorrhea. The PRL level in galactorrhea milk was lower than in serum and was similar to that obtained in normal mature milk. However, significantly higher total solid, total ash, lipid and calcium levels, and reduced lactose and potassium levels were seen in galactorrhea specimens compared to mature milk. Although all the constituents decreased during treatment, the highly significant reduction in lipid and calcium levels shows the predominant effect of PRL on mammary synthesis and/or transport of these constituents. Fasting serum total lipids, total cholesterol and triglyceride levels were significantly higher in the galactorrhea group than in breast-feeding women with established lactation, suggesting that elevated serum PRL plays a role in lipid metabolism.