Statins do not increase the risk of developing type 2 diabetes in familial hypercholesterolemia: The SAFEHEART study

BACKGROUND

Familial Hypercholesterolemia (FH) is the most common monogenic disorder that causes premature coronary artery disease (CAD). Our objective was to examine the risk of new onset type 2 diabetes mellitus (T2DM) among FH patients and unaffected relatives in relation to treatment with different statins in the SAFEHEART cohort study.

METHODS

This is a cross-sectional and prospective cohort study in 2558 FH and 1265 unaffected relatives with a mean follow-up of 5.9 years. Several pertinent data, such as age, gender, metabolic syndrome, lipid profile, body mass index (BMI), waist circumference, HOMA-IR, dose, duration and type of statins, were obtained and examined as predictors of incident diabetes.

RESULTS

The new onset diabetes was 1.7% in FH and 0.2% in non FH patients (p=0.001). In multivariate logistic regression, age (OR 1.02, CI 95%: 1.02-1.08), HOMA-IR (OR 1.17, CI 95%: 1.03-1.33), metabolic syndrome (OR 3.3, CI 95%: 1.32-8.28) and specifically plasma glucose, as a component of metabolic syndrome (OR 15.7, CI 95%: 4.70-52.53) were significant predictors of new onset T2DM in the FH group alone. In the adjusted Cox regression model in FH group, age (HR 1.03, CI 95% 1.00-1.06, p=0.031) and metabolic syndrome (HR 4.16, CI 95% 1.58-10.92, p=0.004) remained significant predictors of new onset T2DM.

CONCLUSIONS

Our data do not support the postulated diabetogenic effect associated with high-dose statins use in our cohort of FH patients.

Evidence for an electrogenic, negatively protein-kinase-A-modulated, Na+-dependent HCO3- transporter in human lymphocytes

We studied the effects of external HCO3- on pHi regulation in human lymphocytes after an acid load. Cells were acidified by preincubation with NH4Cl and pHi recovery was measured with the fluorescent dye BCECF. Cells recovering in HCO3--containing medium reached a higher final pHi, the H+ efflux rate was increased and shifted to alkaline pHi compared to that of cells recovering in HCO3--free solution. The resting pHi was higher in a HCO3--containing solution. Experiments carried out in the presence of amiloride, DIDS and in the absence of external Na+ suggest the existence of two major mechanisms acting in the pHi recovery of lymphocytes after an acid load: an amiloride-sensitive Na+/H+ exchanger and a DIDS-sensitive Na+-dependent HCO3- transporter. The last mechanism could be a Na+/HCO3- cotransporter based on membrane potential changes determined with the potential-sensitive fluorescent probe bis-oxonol. Preincubation of cells with forskolin and H-89 showed protein-kinase-A-dependent downregulation of the amiloride-insensitive recovery of pHi in human lymphocytes. In summary, this paper provides functional evidence for the existence of a Na+/HCO3--dependent mechanism involved in pHi recovery in human lymphocytes following an acid load, that is electrogenic and downregulated by PKA.

[Seronegative systemic lupus erythematosus and autoimmune thyroiditis]

The association of systemic lupus erythematosus (SLE) and autoimmune thyroiditis has been previously described. We report a woman with negative antinuclear antibodies (ANA) and criteria for the diagnosis of SLE. The patient was also diagnosed with autoimmune thyroiditis. We review the clinical characteristics and the association of both entities. We also remark in this case the association of autoimmune thyroiditis with seronegative SLE.

[Different etiology of thyrotoxicosis as a function of previous prevalence of goiter]

BACKGROUND

The high incidence of goiter is believed to modify the characteristics and etiology of thyrotoxicosis. The aim of the present was to study the etiologic types and clinical characteristics of thyrotoxicosis of patients from two areas of different endemic goiter.

METHODS

Two hundred twelve patients (184 women and 28 males) were studied with clinical and analytical data of thyrotoxicosis. The patients were consecutively seen in the endocrinology units of two different hospitals over the last 4 years. One hundred eight patients pertained to the area of the Xeral Hospital in Lugo (inland zone) and 104 pertained to the area of the Juan Canalejo Hospital from La Coruña (coastal zone). The clinical data of thyrotoxicosis, thyroxin concentration and thyroid gammagraphies were evaluated.

RESULTS

The different etiological types were: Graves disease (GD): Lugo: 20 (19%), La Coruña 57 (55%; p less than 0.001). Toxic multinodular goiter (TMG): Lugo 53 (49%), La Coruña 29 (28%; p less than 0.001). Toxic adenoma (TA): Lugo 23 (21%), La Coruña 13 (13%). Hyperthyroidism by iodine: Lugo: 8 (7%), La Coruña 3 (3%). Other diagnosis: Lugo: 4 (3%), La Coruña 2 (2%). Although the frequency of thyrotoxicosis was much greater in women the percentage distribution of the etiologic types was similar in the two sexes. Symptoms were more frequent in patients with GD with respect to TMG. The presence of auricular fibrillation was more frequent in patients with TMG (38%) than in those presenting GD (4%; p less than 0.01).

CONCLUSIONS

Toxic multinodular goiter is the most common cause of thyrotoxicosis in the zones of high endemic goiter. On lowering endemic goiter the percentage of TMG is lowered and that of Graves disease is raised. The symptomatology of thyrotoxicosis is more evident in GD with relation to other etiologic types, but auricular fibrillation is more frequent in TMG. The high prevalence of toxic nodular goiter and hyperthyroidism by iodine suggests the important pathogenic role of the increase of the ingestion of iodine in the form of iodized salt or drugs with iodine.

Study of insulin-like growth factor I in human obesity

In obesity there is a decrease in basal and stimulated GH secretion. IGF-I, which has negative feedback effects on GH secretion, could be the initial mediator of such alterations. We studied IGF-I levels in obese subjects and their relationship to the obesity level and GH secretion. We determined plasma IGF-I, basal and stimulated GH in 30 normal and 30 obese women and related these variables to obesity indices (body mass index, BMI, and % overweight). Baseline plasma GH values were 1.2 +/- 0.3 and 2.3 +/- 0.6 micrograms/l in obese subjects and controls, respectively (NS). Mean peak GH secretion after stimuli were 11.2 +/- 1.4 and 34.4 +/- 5.6 micrograms/l in obese subjects and controls, respectively (p less than 0.001). Plasma IGF-I were 1.0 +/- 0.1 U/ml and 0.7 +/- 0.1 U/l in obese subjects and controls, respectively (NS). There was a significant negative correlation between plasma IGF-I and age (r = -0.55, p less than 0.001) and a significant negative correlation between mean peak GH secretion and weight (r = -0.60, p less than 0.001), BMI (r = -0.64, p less than 0.001) and percentage of ideal body weight (r = -0.67, p less than 0.001). We did not find any correlation between IGF-I and indices of overweight. These data suggest that the reduced GH secretion found in obesity is not related to a negative feedback inhibition by elevated levels of IGF-I and that adiposity is not associated with a decline in IGF-I levels. We confirm the existence of a negative correlation between GH secretion and obesity indices.