[The effect of fluoxetine on insulin resistance in non diabetic obese patients]. / Efecto de fluoxetina sobre la insulino resistencia en pacientes obesos no diabéticos.

Fluoxetine, a serotonin re-uptake inhibitor with antidepressive and appetite reduction effects, could improve insulin sensitivity. The aim of this work was to assess this effect of fluoxetine in obese subjects. We studied 12 subjects with a body mass index over 30, with a normal oral glucose tolerance test and not subjected to dietary restrictions. Insulin sensitivity using Bergman's minimal model, sex hormone binding globulin (SHBG) and insulin like growth factor binding protein 1 (BP 1) were evaluated before and after three weeks of treatment with 60 mg OD of fluoxetine. During treatment, subjects lost a mean of 1.9 kg. When compared with basal values, insulin sensitivity index (S1) improved significantly at the end of treatment (1.71 +/- 0.44 and 2.72 +/- 0.63 respectively), SHBG increased (28.9 +/- 5.1 and 18.2 +/- 3.4 nM/ml respectively) and BP 1 did not change (2.8 +/- 0.9 and 1.5 +/- 0.3 ng/ml respectively). The changes in insulin sensitivity did not correlate with weight changes (r = 0.4 NS). Weight or insulin sensitivity changes did not correlate with initial degree of insulin resistance. We conclude that the improvement in insulin sensitivity elicited by Fluoxetine is not related to weight changes and may be useful in the treatment of insulin resistant obese subjects.

[Improvement of insulin sensitivity associated with the prolonged use of Acipimox in ++a morbid obese patient]. / Mejoría de la insulinosensibilidad asociada al uso prolongado de Acipimox en un obeso mórbido.

Insulin sensitivity was estimated in a morbidity obese, insulin-resistant, glucose-intolerant patient before and after 4 weeks of treatment with Acipimox (250 mg t.i.d), an orally-administered, long-acting antilypolitic drug. The ensuing fall in circulating levels of fasting free fatty acids was associated with a clear amelioration of insulin resistance, as assessed by a minimal model analysis of a frequently sampled intravenous glucose tolerance test as well as by an oral glucose tolerance test. Similarly, this treatment brought about a reappearance of GH response to oral stimulation with clonidine. The evidence showing Acipimox-induced amelioration of insulin resistance in this patient without diet, exercise or weight loss should encourage exploring the potential utility of this drug in this type of patients.

[The clinical estimate of adiposity is not a good predictor of insulin tissue sensitivity measured with a minimal model analysis]. / La estimación clínica de la adiposidad no es un buen predictor de la sensibilidad tisular a la insulina medida con un analisis de modelo mínimo.

Fifteen male volunteers, aged 30 to 40 years old, were classified according to body mass index (BMI) as lean (n = 5, BMI less than 20 kg/m2), normal (n = 5, BMI 20-25) or obese (n = 5, BMI over 30). Glucose intolerance was ruled out by a normal oral glucose tolerance test and insulin sensitivity (SI) and glucose effectiveness (SG) were estimated by a minimal model analysis of a frequently sampled intravenous glucose tolerance test modified by an intravenous insulin injection at minute 20. The MINMOD program was fed with 29 or 12 values (reduced sampling schedule). Despite a significant inverse correlation between BMI and SI (r = -0.533 p < 0.05), the latter parameter overlapped among groups and the correlation was lost when obese individuals were not considered. Waist/hip ratio correlated modestly with SI (r = -0.52 p < 0.05). SG did not correlate with BMI. Using the reduced sampling schedule. SI values had a correlation coefficient of 0.78 with those calculated using the usual sampling schedule, although they were 82% lower. We conclude that only a BMI of over 30 accurately predicts a low SI, and that waist/hip ratio does not have a better predictive power.

[Hyperinsulinemia in thyrotoxic hypokalemic periodic paralysis: 2 clinical cases]. / Hiperinsulinemia en parálisis periódica hipokalémica tirotóxica: 2 casos clínicos.

Thyrotoxic hypokalemic periodic paralysis is infrequent in white populations and its physiopathology is not well known. We report two white male patients (aged 25 and 29 years old) in whom hyperinsulinemia was documented during an episode of hypokalemic paralysis.

[Insulin resistance: a frequent phenomenon in clinical practice]. / Insulinorresistencia, un fenómeno frecuente en clínica.

This review is focused on the diagnostic, clinical and therapeutic aspects of insulin resistance relevant to the clinician. The observed phenomenon of the wide variability of insulin sensitivity in clinically healthy subjects is discussed; qualitative and quantitative aspects of the methodologies currently used for the assessment of insulin sensitivity in the clinical setting are dealt with, as well as their applicability to day-to-day clinical care. The medical consequences of hyperinsulinemia, including dyslipidemia, hypertension coronary artery disease and ovarian hyperandrogenism are likewise discussed. A panoramic view of the various clinical presentations of insulin resistance is also offered, including clinical elements for suspicion, as well as an account of the prevalent, less-prevalent and rare disorders harboring the phenomenon of insulin resistance. The final topic of the review is a novel discussion on the therapeutic possibilities in insulin resistance disorders, including treatment with hormones and antihormones.

[Insulin sensitivity: absence of sexual differences when expressed as a function of lean body mass]. / Sensibilidad a la insulina: ausencia de diferencias, sexuales al expresarla en función de la masa magra.

The hyperinsulinemic, euglycemic clamp technique was used to test the hypothesis that--when expressed per kilogram of lean body mass--there is a sex-difference in peripheral insulin-mediated glucose disposal (M), as proposed in the literature. Lean body mass was assessed with tetrapolar bioelectric impedance analysis. We studied 15 normal subjects (volunteers with normal glucose tolerance and body mass indices between 20-25 kg/m2) of both sexes, 9 women and 6 men, of 2 age-groups, 20-30 year-old and 40-50 year-old. Men and women were similarly aged (33.3 +/- 3.8 and 33.3 +/- 3.8 years, respectively). Body mass indices were similar in both sexes (22.5 +/- 0.6 in women and 23.6 +/- 0.7 in men, NS) but percentages of fat mass were not (29.4 +/- 1.2 in women and 20.6 +/- 1.6 in men, p less than 0.001). As no difference in M (mg of glucose metabolized per kilogram of body weight per minute) between age-groups was found (6.4 +/- 0.8 and 6.8 +/- 1.2 mg/kg/min, NS) the data from these 2 age-groups were pooled. When M values obtained in both sexes were compared no differences were found (7.1 +/- 1.5 mg/kg/min in women and 6.3 +/- 0.6 in men, NS). Similarly, when M was expressed in function of the prevailing insulin levels attained during steady-state, M/l, no differences were disclosed (8.98 +/- 2 mg/kg/min/microIU insulin in women and 7.8 +/- 1.2 in men, NS).(ABSTRACT TRUNCATED AT 250 WORDS)

[Mitral valve prolapse associated with Basedow's disease and active hyperthyroidism. Preliminary report]. / Proplapso valvular mitral asociado a enfermedad de Basedow e hipertiroidismo activo. Comunicacion preliminar.

We performed 2 dimensional echocardiograms to investigate the presence of mitral valve prolapse (MVP) in 21 patients with Graves disease and active hyperthyroidism. 22 healthy subjects were used as a control group. The incidence of MVP was 24% (n = 5) in hyperthyroid patients compared to 5% (n = 1) in normals (NS by Fisher's exact test). Age, T3 and T4 levels were similar in hyperthyroid patients with and without MVP, but the clinical course was longer in the former. A study in a larger group of patients may help establish the increased incidence of MVP in hyperthyroidism.