Reduction in mortality in subjects with homozygous familial hypercholesterolemia associated with advances in lipid-lowering therapy.

BACKGROUND: Homozygous familial hypercholesterolemia is an inherited disorder caused by mutations in both low-density lipoprotein receptor alleles, which results in extremely elevated plasma low-density lipoprotein cholesterol concentrations and very early morbidity and mortality due to cardiovascular disease. METHODS AND RESULTS: To evaluate the impact of advances in lipid-lowering (predominantly statin) therapy on cardiovascular disease morbidity and mortality in a large cohort of patients with homozygous familial hypercholesterolemia, the records of 149 patients (81 females, 68 males) from 2 specialized lipid clinics in South Africa were evaluated retrospectively. Homozygous familial hypercholesterolemia was diagnosed by confirmation of mutations in genes affecting low-density lipoprotein cholesterol or by clinical criteria. A Cox proportional hazard model with time-varying exposure was used to estimate the risk of death and major adverse cardiovascular events among statin-treated patients compared with statin-naive patients. The hazard ratio for benefit from lipid therapy, calculated with the Cox proportional hazards model for the end point of death, was 0.34 (95% confidence interval 0.14-0.86; P=0.02), and for the end point of major adverse cardiovascular events, it was 0.49 (95% confidence interval 0.22-1.07; P=0.07). This occurred despite a mean reduction in low-density lipoprotein cholesterol of only 26.4% (from 15.9±3.9 to 11.7±3.4 mmol/L; P<0.0001) with lipid-lowering therapy. CONCLUSIONS: Lipid-lowering therapy is associated with delayed cardiovascular events and prolonged survival in patients with homozygous familial hypercholesterolemia.

Prevalence of mutations in AGPAT2 among human lipodystrophies.

Berardinelli-Seip congenital lipodystrophy (BSCL) is a heterogeneous genetic disease characterized by near absence of adipose tissue and severe insulin resistance. We have previously identified mutations in the seipin gene in a subset of our patients' cohort. Recently, disease-causing mutations in AGPAT2 have been reported in BSCL patients. In this study, we have performed mutation screening in AGPAT2 and the related AGPAT1 in patients with BSCL or other forms of lipodystrophy who have no detectable mutation in the seipin gene. We found 38 BSCL patients from 30 families with mutations in AGPAT2. Three of the known mutations were frequently found in our families. Of the eight new alterations, six are null mutations and two are missense mutations (Glu172Lys and Ala238Gly). All the patients harboring AGPAT2 mutations presented with typical features of BSCL. We did not find mutations in patients with other forms of lipodystrophies, including the syndromes of Lawrence, Dunnigan, and Barraquer-Simons, or with type A insulin resistance. In conclusion, mutations in the seipin gene and AGPAT2 are confined to the BSCL phenotype. Because we found mutations in 92 of the 94 BSCL patients studied, the seipin gene and AGPAT2 are the two major genes involved in the etiology of BSCL.

Diabetogenic effect of tacrolimus in South African patients undergoing kidney transplantation1.

BACKGROUND: Diabetes mellitus (DM) is a complication of tacrolimus therapy. This prospective study evaluated the prevalence of DM in South African black and white patients receiving tacrolimus after kidney transplantation and factors that could identify patients before transplantation who may be at risk of developing DM. METHODS: Fasting blood samples from 17 patients (11 black, 6 white) were analyzed immediately pretransplantation and at 1 and 3 months posttransplantation for glucose, HbAIC, insulin, C-peptide, free fatty acids, lipids, urea, and creatinine. Insulin resistance (IR) was calculated using the homeostasis model assessment (HOMA) and quantitative insulin sensitivity check index (QUICKI) formulas. RESULTS: Eight patients (47%) became diabetic (six black, two white), and nine patients (five black, four white) remained nondiabetic. Mean glucose concentrations in the diabetic group were significantly higher at 1 month (P=0.03) and 3 months (P=0.01). Mean insulin level was also significantly raised at 3 months (P=0.01) as was HbAIC (P=0.001). C-peptide concentrations did not change significantly in either group. Significant correlations emerged between fasting glucose concentrations at 3 months posttransplantation and initial HOMA (r=0.486; P=0.048) and initial QUICKI (r=-0.582; P=0.014). CONCLUSIONS: Occurrence of DM was high and somewhat greater in black patients. IR was the main mechanism involved, together with inadequate beta-cell compensation. IR pretransplantation predicts the subsequent development of DM.

African women with depression: the effect of imipramine and fluoxetine on body mass index and leptin secretion.

Treatment of depression is often accompanied by weight changes. Previous studies indicate that leptin plays no role in this change despite showing a strong correlation with body mass index (BMI) in healthy people. The aim of this study was to evaluate the effect of imipramine and fluoxetine on BMI and its correlation with leptin. Eighteen depressed female patients randomly received either drug for 3 months. BMI was calculated and fasting blood samples were assayed for glucose, leptin, insulin, free fatty acids (FFA), and lipids. The difference between the changes in BMI (imipramine + 1.0 kg/m2, fluoxetine -0.5 kg/m2) was statistically significant (P < 0.05, t = 2.106). There was a significant positive correlation between overall BMI and leptin (r = 0.784, P < 0.001) but not between BMI and insulin or FFA. However, fasting insulin levels and calculated insulin resistance levels dropped substantially in the imipramine group. We conclude that the use of tricyclic antidepressants (TCAs) in depressed patients at risk for developing type 2 diabetes remains unresolved at this stage.

Longitudinal changes in pituitary-adrenal hormones in South African women with burnout.

The authors' goal was to document baseline pituitary-adrenal hormonal and related metabolic variables in 16 female patients with burnout. Then, following stress management intervention, to compare the changes with an equal number of untreated control subjects. At monthly intervals for 4 mo, 24-h urine samples were obtained for determination of free cortisol excretion. In addition, fasting blood samples were analyzed for levels of cortisol, dehydroepiandrosterone sulfate (DHEAS), ACTH, aldosterone, and catecholamines. Other biochemical measurements included growth hormone, prolactin, insulin, glucose, and lipid components. The Maslach Burnout Inventory, General Health Questionnaire- 28, and Zung depression rating scale were completed on each consecutive visit. The most striking finding was the reduction of urine free-cortisol excretion in the patients compared with controls. Initial urinary free cortisol was significantly lower in the patients (mean +/- SEM = 47.2 +/- 11.0 vs 79.0 +/- 6.8 nmol/L, p = 0.02) and remained significantly reduced at 4 mo (mean +/- SEM = 44.0 +/- 6.1 vs 91.1 +/- 8.8 nmol/L, p = 0.0001). There were no significant changes in the other hormonal and biochemical data. We conclude that there is functional hypocortisolism in burnout, which is not immediately restored on stress management intervention despite clinical and psychological improvement.

High-dose atorvastatin therapy is required for significant improvement of endothelial function in heterozygous familial hypercholesterolaemic patients.

This study evaluated endothelial dysfunction (ED) by measuring flow-mediated vasodilation (FMD) and for six months documented changes in ED, LDL-C levels and serum concentrations of inflammatory markers with high- and low-dose atorvastatin therapy. In 23 heterozygous familial hypercholesterolaemic (FH) patients, FMD, LDL-C and inflammatory markers (sVCAM-1, sICAM-1, E-selectin and highly sensitive C-reactive protein) were measured at baseline (untreated) and on atorvastatin 20 and 80 mg/day. In untreated patients, FMD was significantly reduced (mean +/- SD = 3.09 +/- 0.91%) compared with 10 normocholesterolaemic controls (8.71 +/- 2.41%; p < 0.01). FMD improved non-significantly with atorvastatin 20 mg/day (5.60 +/- 1.17%), but showed a significant improvement (8.54 +/- 1.11%; p < 0.01) with atorvastatin 80 mg/day. LDL-C decreased markedly (-42.4%; p < 0.0001) on 20 mg/day and decreased further (-48.6%; p < 0.05) on 80 mg/day. FMD improvement, however, did not correlate with LDL-C reduction. No significant changes occurred in any inflammatory markers. We concluded that ED was present in untreated FH patients and improved significantly on high-dose atorvastatin. There was no correlation between the changes in FMD and LDL-C, suggesting either a LDLC-independent effect on ED, or that a marked reduction in LDL-C is required to normalise ED in FH.

Basal endocrine status in African dietary iron overload.

Endocrine disturbances, notably diabetes, have been well described as a complication of iron overload due to hereditary hemochromatosis and beta-thalassemia. Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis has also been well documented. The pattern of iron loading in African iron overload with saturated transferrin is similar to that seen in hereditary hemochromatosis. In addition, many symptoms ascribed to pituitary dysfunction are common to both conditions. The present study was undertaken to assess whether a similar pattern of endocrine dysfunction occurs in African iron overload. Thirty subjects with African iron overload and transferrin saturation >50%, plus 30 age and sex matched normal controls were studied. An iron profile, fasting plasma glucose, cortisol, DHEA-S, LH, FSH, growth hormone, prolactin, TSH, and FT4 levels were measured in all 60 subjects as well as testosterone in the males and estradiol in the females. Iron loading in the subjects with increased transferrin saturation ranged from moderate to severe. No significant differences were found in the mean testosterone, estradiol, LH, DHEA-S, growth hormone, prolactin, or TSH levels between the subjects and normal controls. In female subjects, although within the normal range, the mean FSH level was significantly higher, probably due to their being somewhat older and in a more advanced stage of menopause than the control females. Mean cortisol concentrations were increased in both genders in the patient group, significantly so in the females; however, values were within the reference range. We conclude therefore that there appears to be no major impairment of endocrine function in the basal state in African iron overload subjects with moderate to severe degrees of iron loading.