The influence on oral contraceptive formulation on carbohydrate and lipid metabolism.
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Biology↗
Biomedical subjects
R Niththyananthan
Publications and source records attributed to R Niththyananthan.
Comparison of effects of different combined oral-contraceptive formulations on carbohydrate and lipid metabolism.
Oral glucose-tolerance tests were performed and fasting serum cholesterol and triglyceride levels measured in 1628 Caucasian women taking combined oestrogen/progestagen oral contraceptives (o.c.) and 577 women not taking O.C. The former were divided into six groups according to the composition of the O.C Glucose tolerance deteriorated in all O.C. groups containing oestrane progestagens (nortestosterone-derived) or the gonane, norgestrel, but was unaltered by O.C. containing a pregnane progestagen (derived from progesterone). The greatest deterioration was with O.C. containing 75 microgram or more oestrogen, and this was associated with impairment of the early insulin response to glucose. In O.C. containing a pregnane progestagen insulin secretion was unaffected. In the remaining O.C. groups insulin secretion was increased; this was most pronounced with the O.C. containing a gonane progestagen. Serum-cholesterol was elevated only with O.C. containing 75 microgram or more oestrogen and an oestrane progestagen and tended to be lower in O.C. containing a gonane progestagen. O.C.-induced hypertriglyceridaemia was oestrogen-dose-related, and this effect was potentiated by the pregnane progestagen. The gonane progestagen antagonised oestrogen-induced hypertriglyceridaemia.
Adult↗
Increased maternal fasting proinsulin as a predictor of insulin requirement in women with gestational diabetes.
Circulating proinsulin was assessed during a 75g OGTT in 55 pregnant women who fulfilled WHO criteria for impaired glucose tolerance before the 32nd gestational week. Proinsulin was assayed retrospectively using a two-site immunoradiometric assay and immunoreactive insulin by radioimmunoassay. Of the 55 women, 19 required insulin treatment in addition to diet later in pregnancy. Fasting proinsulin concentrations were significantly higher in the 19 women who later required insulin treatment compared with the 36 women treated with diet alone (3.4 +/- 0.7 vs 1.8 +/- 0.2 pmol l-1, p < 0.005). There was no difference between the treatment groups of 60 and 120 min proinsulin values during the OGTT. Fasting plasma glucose and immunoreactive insulin were similar in the insulin-treated and diet-treated women and remained similar during the OGTT. No women within the insulin-treated group had a fasting plasma proinsulin value < 1.1 pmol l-1 in contrast with 12 women in the diet-treated group (p = 0.0123). Ten of the 19 insulin-treated women had a fasting plasma proinsulin > 2.5 pmol l-1 compared with 8 of the 36 diet-treated women (p = 0.0346). Fasting proinsulin values early in pregnancy have prognostic implications in women with gestational diabetes.
Adult↗