Assessment of Levels of Metabolic Hormones and Lipid Profile in Growth Hormone Deficient Patients

Abstract

The current study aims to evaluate levels of metabolic hormones and lipid profile in a sample of growth hormone (GH) deficient patients. Seventy-five GH deficient patients and twenty healthy subjects, used as a control group, participated in this study during their attendance to the National Diabetic Center for Treatment and Research/Al-Mustansiriya University. The studied subjects’ ages were with a range of 3-15 years. Blood samples were collected from the studied subjects to determine basal levels of GH, GH2 and GH3 after 1 hr. and 1:30 hr. of provocation with clonidine. In addition, levels of insulin-like growth factor-1 (IGF-1), metabolic hormones [thyroid profile: triiodothyronine (T3), thyroxin (T4), and thyroid stimulating hormone (TSH) and cortisol], and lipid profile elements [cholesterol, triglyceride, high density lipoprotein (HDL), low density lipoprotein (LDL) and very low density lipoprotein (VLDL)] were studied. The findings of the anthropometric measurements of the studied groups revealed that insignificant (P>0.05) difference was found in the weight between the patients (26.59 ± 1.35 kg) and the control (30.95 ± 2.09 kg), while the mean of height in the patients (123.35 ± 2.18 cm) was significantly (P<0.05) lower than its value in the control (132.72 ± 3.60 cm). Mean BMI values demonstrated insignificant (P>0.05) differences between the patients (16.71 ± 0.54 kg/m2) and the control (17.12 ± 0.55 kg/m2). However, mean BMI percentile and mean BMI Z-score revealed a significant (P<0.05) decrease in the patients (27.90 ± 3.16; -1.107 ± 0.21) compared to their values in the control (44.30 ± 5.75; -0.169 ± 0.16), respectively. The results also showed insignificant (P>0.05) differences in the level of basal GH between the patients (0.39 ± 0.04 ng/ml) and the control (0.57 ± 0.18 ng/ml), while a highly significant (P<0.01) decrease was found in the levels of GH2 (2.97 ± 0.27 ng/ml) and GH3 (2.43 ± 0.23 ng/ml) in the patients group compared to the control group (12.70 ± 0.45 ng/ml; 8.10 ± 0.43 ng/ml), respectively. The Level of IGF-1 showed a significant (P<0.05) decrease in the patients (128.75 ± 10.69 ng/ml) compared to the control (176.85 ± 16.36 ng/ml). The results of metabolic hormones revealed insignificant (P>0.05) differences in the level of serum T3 between the patients (2.39 ± 0.07 nmol/L) and control (2.19 ± 0.12 nmol/L), while a highly significant (P<0.01) decrease was found in serum T4 level in the patients (98.19 ± 1.76 nmol/L) compared to control (114.85 ± 4.42 nmol/L). An insignificant (P>0.05) difference was found in serum TSH between the patients (2.51 ± 0.14 µIU/ml) and control (2.45 ± 0.14 µIU/ml). The data of serum cortisol showed a significant (P<0.05) increase in the patients (138.72 ± 18.05 ng/mL) compared to control (112.61 ± 13.92 ng/mL). The results of lipid profile showed insignificant (P>0.05) differences in serum cholesterol level between the patients (186.34 ± 5.56 mg/dL) and control (150.35 ± 4.31 mg/dL), while triglyceride showed a significant (P<0.05) increase in the patients (88.90 ± 6.19 mg/dL) compared to control (61.40 ± 4.15 mg/dL). An insignificant (P>0.05) difference was found in serum HDL between the patients (44.26 ± 1.72 mg/dL) and control (46.55 ± 1.75 mg/dL), while a significant (P<0.05) increase was found in levels of LDL and VLDL in the patients (110.55 ± 4.99 mg/dL; 17.88 ± 1.23 mg/ml) compared to the control (85.22 ± 5.01 mg/dL; 12.97 ± 0.88 mg/ml), respectively. Distribution of the studied groups according to gender revealed that most of the patients with GHD (60 %) were boys while (40 %) of them were girls, while the control was divided into two subgroups (60 % boys and 40 % girls). Distribution of the studied groups according to BMI values showed that the percentage of underweight was higher in the patients (36%) compared to the control (5%), while the percentage of normal weight was higher in the control (95%) compared to the patients (46.7%). It can be concluded from the present study that the diagnosis of GHD cannot be done at the basal serum of GH. A high level of GH was detected after 1 hr. provocation with clonidine compared with its value after 1.30 hr. provocation. The IGF-1 is an appropriate parameter to expect GHD in children and adolescences whom GHD was detected by GH stimulation testing. Low GH secretion is associated with a high level of cortisol resulting in GHD. Patients with GHD displayed a tendency towards lipids disturbances. Growth hormone deficiency appear to be prevalent in males and predominant in underweight GH deficient patients.