Effects of tibolone or continuous combined oestradiol/norethisterone acetate on glucose and insulin metabolism.

OBJECTIVE: To determine the effects of tibolone or oestradiol (E(2) )/norethisterone acetate (NETA) hormone replacement therapy on glucose and insulin metabolism in postmenopausal women. DESIGN: Single-centre double-blind placebo-controlled randomized clinical trial. SUBJECTS/METHODS: We randomized 105 healthy postmenopausal women to tibolone 2·5 mg daily, continuous combined oral E(2) 2 mg/NETA 1 mg daily or placebo over a 2-year study. We performed intravenous glucose tolerance tests (IVGTT) with measurements of plasma glucose, insulin and C-peptide concentrations and the IVGTT glucose elimination rate, k. Mathematical modelling was performed to determine measures of insulin sensitivity, S(i) , pancreatic insulin secretion and hepatic and plasma insulin elimination. RESULTS: Tibolone decreased S(i) to 53-63% and k to 72-79% of baseline values but increased IVGTT phase 2 C-peptide concentrations 1·6-1·8-fold and pancreatic insulin secretion 2·2-2·4-fold, so overall IVGTT glucose concentrations were unaffected. Similar, but for k, significantly smaller changes in insulin and C-peptide secretion were seen with E(2) /NETA, also with no effect on overall IVGTT glucose concentrations. CONCLUSIONS: Tibolone reduces insulin sensitivity. Healthy postmenopausal women seem able to compensate for this and maintain normal postload glucose concentrations, but it may not be advisable to prescribe tibolone to women with, or at increased risk for, diabetes.

Randomized trial of effects of continuous combined HRT on markers of lipids and coagulation in women with acute coronary syndromes: WHISP Pilot Study.

AIMS: Randomized trials have not demonstrated coronary heart disease benefit from hormone replacement therapy (HRT). We hypothesized that low-dose HRT may avoid harm. METHODS AND RESULTS: We studied the effects of HRT on lipids and coagulation in women with acute coronary syndromes. A total of 100 post-menopausal women >55 years were enrolled between 2 and 28 days after an acute coronary syndrome and randomized to oral oestradiol-17beta 1 mg plus norethisterone acetate 0.5 mg daily, or matching placebo, and followed for up to 12 months. Levels of lipids, lipoproteins, and haemostasis markers were measured at baseline, 3, and 6 months. There were no significant differences in lipid levels between the two groups, probably due to concomitant statin use. Antithrombin and factor VII levels were significantly lower in the HRT group, whereas fibrinogen was significantly decreased in the placebo group. No evidence of increased coagulation activation was observed, nor of adverse cardiovascular outcomes [odds ratio (OR) 0.63 (95% confidence intervals 0.31-1.31)]. CONCLUSION: Low-dose HRT may give cardiovascular benefit. These findings require confirmation in a full clinical trial with evaluation of cardiovascular outcomes as the primary objective.

Impaired insulin sensitivity as an independent risk factor for mortality in patients with stable chronic heart failure.

OBJECTIVES: The aim of this study was to determine the significance of insulin resistance as an independent risk factor for impaired prognosis in patients with chronic heart failure (CHF). BACKGROUND: In CHF, impaired insulin sensitivity (S(I)) indicates abnormal energy metabolism and is related to decreased exercise capacity and muscle fatigue. The relationship between insulin resistance (i.e., low S(I)) and survival in patients with CHF has not been established. METHODS: We prospectively studied 105 male patients with CHF due to ischemic (63%) or non-ischemic (37%) etiology. All patients were in clinically stable condition (age 62 +/- 1 year, New York Heart Association [NYHA] functional class 2.6 +/- 0.1, left ventricular ejection fraction [LVEF] 28 +/- 2%, peak oxygen uptake [Vo(2)] 18.2 +/- 0.7 ml/kg/min). Insulin sensitivity was assessed from glucose and insulin dynamic profiles during an intravenous glucose tolerance test using the minimal model technique. RESULTS: During a mean follow-up period of 44 +/- 4 months, 53 patients (50%) died. Patients with S(I) below the median value (median: 1.82 min(-1) x microU x ml(-1).10(4); n = 52) had worse survival (at two years 61% [range 47% to 74%]) than patients with S(I) above the median value (n = 53; at two years 83% [range 73% to 93%]; risk ratio [RR] 0.38, 95% confidence interval [CI] 0.21 to 0.67; p = 0.001). Both patient groups were similar in terms of age, NYHA functional class, and body composition parameters (dual-energy X-ray absorptiometric scan; p > 0.2), but patients with a lower S(I) had a lower LVEF (24 +/- 2% vs. 33 +/- 3%) and peak Vo(2) (16.8 +/- 1.0 ml/kg/min vs. 19.7 +/- 1.0 ml/kg/min; both p < 0.05). On univariate Cox analysis, higher S(I) predicted better survival (RR 0.56, 95% CI 0.35 to 0.89; p = 0.015). On stepwise multivariate analysis, S(I) predicted mortality independently of other variables. CONCLUSIONS: In patients with CHF, lower S(I) relates to higher mortality, independent of body composition and established prognosticators. Impaired S(I) may have implications in the pathophysiology of CHF disease progression. Therapeutically targeting impaired insulin sensitivity may potentially be beneficial in patients with CHF.

Randomized trial of effect of transdermal continuous combined hormone replacement therapy on cardiovascular risk markers.

Whether hormone replacement therapy (HRT) is beneficial for coronary heart disease (CHD) is controversial. We hypothesized that continuous combined transdermal HRT may have benefits on CHD risk markers without the potential adverse effects seen with certain other HRT regimens. Sixty apparently healthy postmenopausal women, aged 40-65 years, entered a prospective, double-blind, randomized, placebo-controlled clinical trial; 55 women completed the 6-month study. Women received either transdermal oestradiol 17beta 0.05 mg and norethisterone acetate 0.125 mg daily, or identical placebo. Circulating markers of vascular function and remodelling, forearm blood flow, lipids and lipoproteins, glucose and insulin, and haemostatic safety parameters were measured at baseline and after treatment. Compared with placebo after 6 months, HRT administration resulted in decreased E-selectin (P < 0.01), and angiotensin-converting-enzyme (ACE; P = 0.05). Cholesterol (P < 0.05), low-density lipoproteins (LDL; P < 0.05), high-density lipoprotein3 (HDL3; P < 0.05) and apolipoproteins AII (P < 0.05) and B (P < 0.05), and fasting insulin (P < 0.05) also decreased in the HRT group. Factor VII coagulation activity decreased (P < 0.01) and plasminogen activator inhibitor-1 and fibrin D-dimer increased (P < 0.05) in the HRT group, whilst prothrombin fragment 1 + 2 (P < 0.05) decreased, more so in the placebo group. There were no changes in matrix metalloproteinase (MMP)-2, or in LDL particle size. This transdermal HRT had beneficial effects on vascular function and CHD risk markers.

Effects of oestrogen-only and oestrogen-progestogen replacement therapy upon circulating angiotensin I-converting enzyme activity in postmenopausal women.

OBJECTIVE: Levels of angiotensin I-converting enzyme (ACE) in blood are associated with variation in cardiovascular disease risk. Serum ACE activity in women may be reduced by combined oestrogen-progestogen hormone replacement therapy (HRT). However, the relative contribution of each hormonal component to this observation is uncertain. We investigated ACE activity in two groups of healthy postmenopausal women receiving HRT regimens. DESIGN: The first group received placebo or oestrogen-only HRT randomly (oral conjugated equine oestrogens or transdermal 17 beta-oestradiol). The second group was treated with oestrogen-only HRT (oral 17 beta-oestradiol) followed by sequential oestrogen-progestogen HRT (17 beta-oestradiol and dydrogesterone). MEASUREMENTS: Assay of blood for soluble ACE activity before and whilst receiving HRT. RESULTS: In the first group, oral conjugated equine oestrogens significantly reduced (P < 0.01) ACE activity by 18% on average relative to pretreatment whereas non-significant changes of -9% and +7% were seen with transdermal 17 beta-oestradiol or placebo treatment, respectively. In the second group oestrogen-only HRT significantly reduced (P < 0.001) ACE activity by 15% on average. The reduction during both the oestrogen-only and combined phases of sequential treatment was 12% and 19%, respectively, compared with pretreatment values (P < 0.01 and P < 0.001). ACE activity also differed significantly (P < 0.05) between the two phases of sequential treatment. CONCLUSIONS: Both oestrogen-only and oestrogen-progestogen HRT may reduce ACE activity in blood. Oestrogen and progestogen may exhibit additive effects on blood ACE activity.