Leptin levels in patients with thalassemia major.

AIM: Patients with thalassemia major often present endocrine abnormalities due to dysfunction in their hypothalamic-pituitary axis. Leptin, an adipocyte derived hormone, primarily acts in hypothalamus and its deficiency in the ob/ob mouse results in persistent immaturity of its hypothalamic-pituitary function. The aim of the study was to evaluate leptin levels in thalassemic patients. METHODS: The study involved 33 adult patients (11 males), mean age (SD) 19.3 years (4.4) and a group of 12 prepubertal boys, mean age (SD): 7 years (1.7) with homozygous beta-thalassemia. RESULTS: Mean (SD) leptin concentration was 3.2 (3.3) ng/mL in thalassemic males and 8.6 (3.3) ng/mL in thalassemic females; values significantly lower than matched normal subjects. In the group of prepubertal thalassemic children, leptin levels were also lower compared with matched healthy children, although the difference was not statistically significant. CONCLUSIONS: In conclusion, low leptin levels were observed in thalassemic patients, which may be due to a toxic effect of iron to adipocytes.

Ultrasonography of the pancreas, as a function index, in children with beta-thalassemia.

Increased echogenicity of the pancreas, due to hemosiderosis, is a frequent laboratory finding in children and adolescents with beta-thalassemia. The aim of this study was to investigate whether increased echogenicity of the pancreas is associated with dysfunction. The ultrasonic image of the pancreas was examined in 34 children aged 12+/-3.8 years old and was compared to the endocrine and exocrine functioning of the gland. Oral glucose tolerance test (OGTT) was performed with simultaneous measurement of insulin and serum trypsin. Twenty-six of the 34 patients (76.5%) presented increased echogenicity, while 8 (23.5%) had a normal ultrasonic pancreatic image. 77% of the patients with increased echogenicity had abnormal OGTT, 46%, with subnormal or increased insulin values, and 32.5% manifested low levels of trypsin. Among the patients with normal ultrasound, 25% had abnormal OGTT and 37.5% abnormal insulin values. Statistical analysis with Student's t-test revealed that patients with increased echogenicity had significantly higher glucose values on OGTT at 60: 7.6 +/- 1.8 mmol/l (137.3 +/- 33.7 mg/dl) as compared to the patients with normal ultrasound: 6.1 +/- 1.2 mmol/l (110.75 +/- 21.72 mg/dl) (p<0.05). Insulin values were significantly affected at 30, 60, and 90 min: 570+/-301, 332+/-156, 294+/-158 pmol/l (79.54 +/- 42, 46.4 +/- 21.8, 41.04 +/- 22 mU/l) respectively in patients with increased echogenicity in comparison to those with normal ultrasonographic image of the gland: 301 +/- 170, 192 +/- 52, 135 +/- 63 pmol/l (42 +/- 23.7, 26.85 +/- 7.36, 18.9 +/- 8.8 mU/l) (p<0.05). No statistical significance was observed between the two groups regarding trypsin levels, even though abnormal values were observed in more children with increased echogenicity than in patients with a normal ultrasound. The above findings confirm that increased echogenicity of the pancreas is associated with disturbance of its function. This simple imaging method could be used as a rough early index of detection of an increased risk for developing diabetes mellitus in patients with beta-thalassemia.

Arterial blood pressure changes in children and adolescents with insulin-dependent diabetes mellitus.

Diabetic nephropathy may develop in childhood and is often related to hypertension. The 24-hour ambulatory blood pressures were measured in 63 children with insulin-dependent diabetes mellitus and were compared with those of 54 healthy siblings. The patients were without clinical complications. The 24-hour recording of their blood pressures revealed higher 24-hour systolic blood pressure (SBP) (115.8 +/- 8.2), 24-hour diastolic blood pressure (DBP) (67.5 +/- 4.6), 24-hour mean arterial pressure (MAP) (81.8 +/- 5.2) compared with control subjects: 24-hour SBP (112.7 +/- 6.7), 24-hour DBP (64.7 +/- 4.1), 24-hour MAP (78.9 +/- 4.5) (p = 0.03, p = 0.001, p = 0.002, respectively). Of the daytime blood pressures, SBP, DBP, MAP were also higher (117.7 +/- 8.7, 69.7 +/- 5.2, 83.8 +/- 5.8) compared with those of siblings (114.9 +/- 6.9, 67.3 +/- 4.3, 81.1 +/- 4.9) (p = 0.05, p = 0.009, p = 0.008, respectively). Of the nighttime blood pressures, SBP, DBP, MAP were higher in patients (108.7 +/- 8.9, 59.5 +/- 6.9, 74.6 +/- 6.9) compared with control subjects (104.8 +/- 7.0, 55.1 +/- 5.0, 70.5 +/- 5.1) (p = 0.01, p = 0.0002, p = 0.0006, respectively). Furthermore, the blood pressure burden was evaluated. Blood pressure burden was defined as the percentage of the increased blood pressure readings greater than the 95th percentile divided by the total number of recorded blood pressures during a corresponding period. Patients had a 43% higher 24-hour SBP burden (19.6 +/- 16.5) and a 50% higher 24-hour DBP burden (12.3 +/- 9.6) in relation to that of control subjects (13.7 +/- 12.8, 8.3 +/- 12.3) (p = 0.03, p = 0.009, respectively). The SBP burden (17.9 +/- 14.6) and DBP burden (11.5 +/- 9.2) of the day was approximately 50% higher in the patients in the relation to control subjects (11.9 +/- 11.1, 7.8 +/- 6.7) (p = 0.01, p = 0.01, respectively). Therefore it seems that hemodynamic changes may appear early in children with diabetes.

Myocardial trophic effects of blood pressure in children with insulin-dependent diabetes mellitus.

To evaluate the effect of blood pressure (BP) on the left ventricular mass index (LVMI), 66 children with IDDM 13 +/- 3 years of age were studied and compared with 58 healthy age-matched siblings. The 24 h BP recordings disclosed that children with diabetes had higher DBP (68 vs. 65 mm Hg, P = 0.002), especially at night (60 vs. 55 mm Hg, P = 0.00007), with a minimisation of the normal nocturnal hypotension (-9.9 vs. -12.4 mm Hg, P = 0.04). Their LVMI was higher (79 vs. 71 g/m2, P = 0.02); it was independent of BP values and variability (P = NS), but it was positively correlated with heart rate (r = -0.46, P = 0.0005). In the control group, LVMI was significantly correlated with the mean SBP (r = 0.46, P = 0.0005); with its variability (r = 0.32, P = 0.02) and, to a lower extent, with heart rate (r = -0.29, P = 0.03). It is concluded that in children with diabetes mellitus the participation of BP in myocardial hypertrophy is not so obvious, although the BP load is increased. The increase of the LVMI occurs early in life and before the onset of hypertension.