ABSTRACT
Up to now it is unclear whether there is a relationship between insulin resistance and circulating leptin levels (LEP) in women with polycystic ovary syndrome (PCOS). To assess the role of LEP in PCOS and to clarify the relationship between plasma LEP levels and insulin resistance (IR) in PCOS patients, we studied 49 women with PCOS and 14 normal premenopausal women. All subjects were evaluated by a 2 hours, 75 g, oral glucose tolerance test. Fasting plasma LEP, insulin, glucose, insulin sensitivity indexes and LEP:body mass index (BMI) were determined. Results were analyzed by ANOVA and the Pearson's correlation test when appropriate. The results indicate that: 1) no differences were found in basal plasma LEP levels (ng/ml) between normal (17.6 +/- 4.9) and PCOS (21.9 +/- 2.8) women; 2) in PCOS patients, a significant (P < 0.01) correlation between plasma LEP levels and BMI and insulin sensitivity indexes were found; and 3) seventeen PCOS patients were insulin resistant (IR) and showed higher basal plasma LEP levels (32.8 +/- 4.3, P < 0.01) and LEP:BMI (0.95 +/- 0.09, P < 0.05) than non insulin resistant (non IR) PCOS subjects (16.2 +/- 3.2 and 0.61 +/- 0.08, respectively). Our results suggest that PCOS seems to be associated with normoleptinemia, however, if IR are analyzed separately from non IR PCOS patients, there is a clear relationship between IR PCOS and hyperleptinemia, regardless of the BMI. The present study strongly supports bi-directional relationship between fat and carbohydrate metabolisms under a very particular physiopathological condition (PCOS).
Subject(s)
Insulin Resistance , Leptin/blood , Polycystic Ovary Syndrome/blood , Adolescent , Adult , Biomarkers/blood , Female , Glucose Tolerance Test , Humans , Leptin/physiology , Polycystic Ovary Syndrome/physiopathologyABSTRACT
La presencia de resistencia insulínica (RI) es un hecho frecuentemente asociado al síndrome de ovario poliquístico (PCO), sin embargo aún no está clara la relación existente entre la RI y los niveles circulantes de leptina en estas pacientes. En este trabajo investigamos los niveles plasmáticos de leptina en pacientes con PCO y evaluamos su relación con la presencia de RI. Se seleccionaron 49 pacientes con PCO y 14 mujeres normales. A todas las pacientes se les realizó un test de tolerancia oral a la glucosa. Se dosó leptina (LEP), insulina y glucosa séricas durante las 2 hs del test y se determinaron los índices de sensibilidad insulínica y relación leptina: índice de masa corporal (LEP:BMI). 1) No observamos diferencias significativas en los niveles séricos de LEP (ng/ ml) entre las pacientes PCO (21.9 ± 2.8) y los controles normales (17.6 ± 4.9). 2) En las pacientes con PCO, los niveles séricos de LEP y el índice LEP:BMI se correlacionaron en forma significativa con el BMI y los índices de sensibilidad insulínica (P<0.01). 3) Diecisiete pacientes con PCO que presentaron RI evidenciaron niveles significativamente mayores de leptina sérica (32.8 ± 4.3 vs. 16.2 ± 3.2, P<0.01) y LEP:BMI (0.95 ± 0.09 vs. 0.61 ± 0.08, P<0.05) que las pacientes sin RI. En conclusión, nuestros resultados evidencian que el síndrome PCO pareceríacursar con normoleptinemia, sin embargo la presencia de RI podría estar relacionada con un aumento de laconcentración de leptina sérica independientemente del BMI. Estos resultados avalan la existencia de una interrelación leptina ¹ insulina en este grupo de pacientes.(AU)
Subject(s)
Humans , Female , Adolescent , Adult , Leptin/blood , Polycystic Ovary Syndrome/blood , Insulin Resistance , Leptin/physiology , Polycystic Ovary Syndrome/physiopathology , Glucose Tolerance TestABSTRACT
Up to now it is unclear whether there is a relationship between insulin resistance and circulating leptin levels (LEP) in women with polycystic ovary syndrome (PCOS). To assess the role of LEP in PCOS and to clarify the relationship between plasma LEP levels and insulin resistance (IR) in PCOS patients, we studied 49 women with PCOS and 14 normal premenopausal women. All subjects were evaluated by a 2 hours, 75 g, oral glucose tolerance test. Fasting plasma LEP, insulin, glucose, insulin sensitivity indexes and LEP:body mass index (BMI) were determined. Results were analyzed by ANOVA and the Pearsons correlation test when appropriate. The results indicate that: 1) no differences were found in basal plasma LEP levels (ng/ml) between normal (17.6 +/- 4.9) and PCOS (21.9 +/- 2.8) women; 2) in PCOS patients, a significant (P < 0.01) correlation between plasma LEP levels and BMI and insulin sensitivity indexes were found; and 3) seventeen PCOS patients were insulin resistant (IR) and showed higher basal plasma LEP levels (32.8 +/- 4.3, P < 0.01) and LEP:BMI (0.95 +/- 0.09, P < 0.05) than non insulin resistant (non IR) PCOS subjects (16.2 +/- 3.2 and 0.61 +/- 0.08, respectively). Our results suggest that PCOS seems to be associated with normoleptinemia, however, if IR are analyzed separately from non IR PCOS patients, there is a clear relationship between IR PCOS and hyperleptinemia, regardless of the BMI. The present study strongly supports bi-directional relationship between fat and carbohydrate metabolisms under a very particular physiopathological condition (PCOS).
ABSTRACT
La presencia de resistencia insulínica (RI) es un hecho frecuentemente asociado al síndrome de ovario poliquístico (PCO), sin embargo aún no está clara la relación existente entre la RI y los niveles circulantes de leptina en estas pacientes. En este trabajo investigamos los niveles plasmáticos de leptina en pacientes con PCO y evaluamos su relación con la presencia de RI. Se seleccionaron 49 pacientes con PCO y 14 mujeres normales. A todas las pacientes se les realizó un test de tolerancia oral a la glucosa. Se dosó leptina (LEP), insulina y glucosa séricas durante las 2 hs del test y se determinaron los índices de sensibilidad insulínica y relación leptina: índice de masa corporal (LEP:BMI). 1) No observamos diferencias significativas en los niveles séricos de LEP (ng/ ml) entre las pacientes PCO (21.9 ± 2.8) y los controles normales (17.6 ± 4.9). 2) En las pacientes con PCO, los niveles séricos de LEP y el índice LEP:BMI se correlacionaron en forma significativa con el BMI y los índices de sensibilidad insulínica (P<0.01). 3) Diecisiete pacientes con PCO que presentaron RI evidenciaron niveles significativamente mayores de leptina sérica (32.8 ± 4.3 vs. 16.2 ± 3.2, P<0.01) y LEP:BMI (0.95 ± 0.09 vs. 0.61 ± 0.08, P<0.05) que las pacientes sin RI. En conclusión, nuestros resultados evidencian que el síndrome PCO pareceríacursar con normoleptinemia, sin embargo la presencia de RI podría estar relacionada con un aumento de laconcentración de leptina sérica independientemente del BMI. Estos resultados avalan la existencia de una interrelación leptina - insulina en este grupo de pacientes.
Subject(s)
Humans , Female , Adolescent , Adult , Insulin Resistance , Leptin , Polycystic Ovary Syndrome/blood , Glucose Tolerance Test , Leptin , Polycystic Ovary Syndrome/physiopathologyABSTRACT
Among neurodegenerative diseases, Alzheimer's disease (AD) is a leading cause of death in elderly individuals. AD is characterized, among other clinical findings, by unexplained weight loss, cachexia and altered immune function. To explore whether any relationship between gender and circulating levels of several eating-controlling metabolites exist, we evaluated leptin, tumor necrosis factor (TNF)-alpha, triiodothyronine (T(3)), free (F) thyroxine (T(4)), TSH, PRL, insulin (INS), and cortisol in 15 AD-treated patients (age range 55-82 years): 9 postmenopausal females (without hormone replacement therapy) and 6 males. The results (mean +/- SEM) indicated that circulating leptin levels were significantly (p < 0.05) higher in female AD (40.34 +/- 11.1 ng/ml) than in male AD (6.07 +/- 1.39 ng/ml) patients. The difference found in circulating leptin levels was noticed regardless of BMI (26.75 +/- 1.77 and 24.55 +/- 1.93 kg/m(2), in females and males, respectively) and waist:hip ratios (0.91 +/- 0.03 and 0.94 +/- 0.02, in females and males, respectively). Moreover, serum TNF-alpha concentrations were also significantly (p < 0.02) higher in AD females (12.24 +/- 1.47 pg/ml) than in AD males (6.62 +/- 1.44 pg/ml), regardless of TNF-alpha:BMI ratios (0.50 +/- 0.09 and 0.28 +/- 0.08, in females and males, respectively; p > 0.05). Finally, no differences were observed between gender (in female and male AD patients, respectively) in circulating levels of T(3) (151.33 +/- 9.91 vs. 116 +/- 17.04 ng/dl), FT(4) (1.26 +/- 0.08 vs. 1.24 +/- 0.06 ng/dl), TSH (1.28 +/- 0.16 vs. 2.46 +/- 0.67 microIU/ml), PRL (10.53 +/- 2.47 vs. 12.61 +/- 2.37 ng/ml), INS (11.76 +/- 1.95 vs. 8.59 +/- 1.34 microIU/ml) and cortisol (15.71 +/- 1.23 vs. 12.63 +/- 1.47 microg/dl). These results indicate that our AD group of patients, with normal corticoadrenal and thyroid functions and normoprolactinemia, displayed a gender-related characteristic in the circulating levels of two very important anorectic signals, leptin and TNF-alpha, being both higher in female than in male AD patients, regardless of BMI. Our study suggests that increased circulating levels of both anorexigenic adipokines may contribute to the metabolic changes observed in AD females.