Kidney growth and renal functions under the growth hormone replacement therapy in children

Exploring the complex dynamics of BMI, age, and physiological indicators in early adolescents

BACKGROUND AND OBJECTIVES

To investigate the relationship between body mass index (BMI) and blood biochemical indicators in early adolescence, and to provide ideas for early prevention of diseases and explore possible disease-related predictors.

METHODS

3125 participants aged 10 ∼ 14 years were selected from China from the survey of "China Nutrition and Health Surveillance ( 2016 ∼ 2017 ) ". Employing advanced statistical methods, including generalized linear models, heatmaps, hierarchical clustering, and generalized additive models, the study delved into the associations between BMI and various biochemical indicators.

RESULTS

In early adolescence, indicators including systolic pressure, diastolic pressure, weight, height, BMI, hemoglobin, blood uric acid, serum creatinine, albumin, vitamin A presented increasing trends with the increase of age ( P < 0.05 ), whereas LDL-C, vitamin D, and ferritin showed decreasing trends with the increase of age ( P < 0.05 ). The increase in hemoglobin and blood uric acid levels with age was more pronounced in males compared to females ( P < 0.05 ). BMI was positively correlated with blood glucose, hemoglobin, triglyceride, LDL-C, blood uric acid, serum creatinine, ferritin, transferrin receptor, hs-CRP, total protein, vitamin A ( P < 0.05 ). There was a significant BMI × age interaction in the correlation analysis with LDL-C, transferrin receptor, serum creatinine, and hs-CRP ( P < 0.05 ). BMI was a risk factor for hypertension, hypertriglyceridemia, low high density lipoprotein cholesterolemia, and metabolic syndrome in all age groups ( OR > 1, P < 0.05 ).

CONCLUSIONS

High BMI was a risk factor for hypertension, hypertriglyceridemia, low high density lipoprotein cholesterolemia, and MetS in early adolescents. With the focus on energy intake beginning in early adolescence, the maintenance of a healthy weight warrants greater attention.

Metabolic Effects of Recombinant Human Growth Hormone Replacement Therapy on Juvenile Patients after Craniopharyngioma Resection

Objective: To investigate the effect of short-term recombinant human growth hormone (rhGH) replacement therapy on metabolic parameters in juvenile patients following craniopharyngioma (CP) resection. Methods. This retrospective study included 42 cases of juvenile patients that had undergone CP resection in the Department of Endocrinology at the Peking Union Medical College Hospital, from April 2013 to August 2020. According to whether they received growth hormone replacement therapy, the patients were divided into either the growth hormone replacement therapy (GHRT) group (30 cases) or the control group (12 cases). Changes in body mass index (BMI), BMI z-score, transaminase activity, fasting blood glucose (FBG) levels, blood lipid profile, and high-sensitivity C-reactive protein (hsCRP) levels were evaluated after one year of GHRT treatment. Results. The average age of the GHRT group was 13.00 (8.00-14.00) years old and these patients had undergone a CP operation an average of 2.00 (1.62-3.15) years earlier. Prior to receiving GHRT treatment, they received appropriate doses of adrenocortical hormone and thyroid hormone replacement therapy. After one year of GHRT treatment, the average BMI z-score decreased from 1.60 ± 1.76 to 1.13 ± 1.73 (P=0.005). Alanine aminotransferase (ALT) activity decreased from 26.50 (17.00∼98.00) U/L to 18.00 (13.00∼26.48) U/L (P ≤ 0.001), and similar changes were observed with regard to aspartate aminotransferase (AST) and glutamyl transferase (GGT) activity in the GHRT treatment group. The average total cholesterol (TC) decreased from 4.67 (4.10-6.14) mmol/L to 4.32 ± 0.85 mmol/L (P=0.002), and low-density lipoprotein (LDL) levels decreased from 3.05 ± 0.95 mmol/L to 2.56 ± 0.65 mmol/L (P=0.001) in the GHRT treatment group. The average blood urea nitrogen level decreased from 4.53 ± 1.09 mmol/L to 3.92 ± 0.82 mmol/L (P=0.016) and the average serum creatinine (SCr) level decreased from 55.59 ± 12.54 µmol/L to 51.15 ± 10.51 µmol/L (P=0.005) in the GHRT treatment group. The average hsCRP level decreased from 3.23 (1.79∼4.34) mg/L to 0.92 (0.42∼1.21) mg/L in the GHRT treatment group. In the control group, the average ALT activity increased from 26.58 ± 8.75 U/L to 42.58 ± 24.59 U/L (P=0.039), GGT activity increased from 19.0 (13.25-29.25) U/L to 25.00 (14.75-34.75) U/L (P=0.026), and LDL levels increased from 2.27 ± 0.76 mmol/L to 3.43 ± 1.28 mmol/L (P=0.04). Conclusion. GHRT treatment improves the metabolic parameters of juvenile patients that have undergone craniopharyngioma resection by reducing BMI z-scores, low-density lipoprotein, and hsCRP levels and improving liver function.

Growth Hormone and IGF1 Actions in Kidney Development and Function

Growth hormone (GH) exerts multiple effects on different organs including the kidneys, either directly or via its main mediator, insulin-like-growth factor-1 (IGF-1). The GH/IGF1 system plays a key role in normal kidney development, glomerular hemodynamic regulation, as well as tubular water, sodium, phosphate, and calcium handling. Transgenic animal models demonstrated that GH excess (and not IGF1) may lead to hyperfiltration, albuminuria, and glomerulosclerosis. GH and IGF-1 play a significant role in the early development of diabetic nephropathy, as well as in compensatory kidney hypertrophy after unilateral nephrectomy. Chronic kidney disease (CKD) and its complications in children are associated with alterations in the GH/IGF1 axis, including growth retardation, related to a GH-resistant state, attributed to impaired kidney postreceptor GH-signaling and chronic inflammation. This may explain the safety of prolonged rhGH-treatment of short stature in CKD.

Renal effects of growth hormone in health and in kidney disease

Growth hormone (GH) and its mediator insulin-like growth factor-1 (IGF-1) have manifold effects on the kidneys. GH and IGF receptors are abundantly expressed in the kidney, including the glomerular and tubular cells. GH can act either directly on the kidneys or via circulating or paracrine-synthesized IGF-1. The GH/IGF-1 system regulates glomerular hemodynamics, renal gluconeogenesis, tubular sodium and water, phosphate, and calcium handling, as well as renal synthesis of 1,25 (OH)2 vitamin D3 and the antiaging hormone Klotho. The latter also acts as a coreceptor of the phosphaturic hormone fibroblast-growth factor 23 in the proximal tubule. Recombinant human GH (rhGH) is widely used in the treatment of short stature in children, including those with chronic kidney disease (CKD). Animal studies and observations in acromegalic patients demonstrate that GH-excess can have deleterious effects on kidney health, including glomerular hyperfiltration, renal hypertrophy, and glomerulosclerosis. In addition, elevated GH in patients with poorly controlled type 1 diabetes mellitus was thought to induce podocyte injury and thereby contribute to the development of diabetic nephropathy. This manuscript gives an overview of the physiological actions of GH/IGF-1 on the kidneys and the multiple alterations of the GH/IGF-1 system and its consequences in patients with acromegaly, CKD, nephrotic syndrome, and type 1 diabetes mellitus. Finally, the impact of short- and long-term treatment with rhGH/rhIGF-1 on kidney function in patients with kidney diseases will be discussed.

Renal function in short-statured children born small for gestational age and treated with growth hormone

BACKGROUND

Children born small for gestational age (SGA), particularly when associated with an extremely low birthweight (ELBW), have a higher risk of renal dysfunction. Growth hormone (GH) treatment is used to treat short-statured children born SGA; however, its effects on renal function remain elusive, especially in those born SGA with ELBW.

METHODS

Short-statured children born SGA (N = 42) were included. Subjects were subdivided into two groups based on their birthweight: the ELBW group (N = 15) with a birthweight of <1,000 g, and the non-ELBW group (N = 27) with birthweights ranging between 1,000 and 2,500 g. The creatinine-based estimated glomerular filtration rates (eGFR) before (pre-eGFR) and 5 years after GH treatment (post-eGFR) were compared. Correlations between eGFR, anthropometric, or birth parameters, and cumulative GH dose were evaluated using Spearman's rank correlation coefficient.

RESULTS

The ELBW group had a lower pre- and post-eGFR than the non-ELBW group. Five-year GH treatment did not significantly reduce eGFR in either group. Post-eGFR was positively associated with gestational week and birthweight. However, the cumulative GH dose was not correlated with pre-eGFR, post-eGFR, or percentage change in eGFR (%ΔeGFR). The change in bodyweight standard deviation score during GH treatment was positively correlated with %ΔeGFR in the ELBW group.

CONCLUSIONS

The current results indicated that GH treatment was unlikely a risk for the reduction in eGFR in short-statured children born SGA. However, eGFR should be carefully monitored, especially in those born SGA with ELBW because these subjects had lower eGFR than non-ELBW subjects.

Glomerular filtration rate, blood pressure and microalbuminuria in adults born SGA: A 5-year longitudinal study after cessation of GH treatment

BACKGROUND

Growth hormone treatment increases glomerular filtration rate (GFR), as serum IGF-I stimulates the renin-angiotensin system. Infants born with a low birth weight have a smaller number of nephrons, which cause a lower GFR, a higher blood pressure and a higher albumin-to-creatinine ratio in early adulthood.

METHOD

A total of 261 young adults born SGA, previously treated with growth hormone (SGA-GH), were longitudinally followed. Glomerular filtration rate, based on serum creatinine levels, was determined at cessation of GH treatment and at 6 months, 2 years and 5 years thereafter. Glomerular filtration rate, blood pressure and urinary albumin-to-creatinine ratio at 5 years after cessation of GH were compared with untreated age-matched controls (56 untreated short subjects born SGA [SGA-S], 118 subjects born SGA with spontaneous catch-up growth [SGA-CU], 135 subjects born appropriate for gestational age [AGA]).

RESULTS

Glomerular filtration rate decreased significantly only during the first 6 months after cessation of GH treatment, while remaining well within the normal range (124.6 vs 120.2 mL/min/1.73 m² , P < .001). SGA-GH adults had a similar GFR, blood pressure and urinary albumin-to-creatinine ratio as the healthy controls born SGA and AGA.

CONCLUSION

In conclusion, our 5 years longitudinal follow-up study shows a decrease in GFR during 6 months after GH cessation, but thereafter GFR remained stable and within the normal range. Glomerular filtration rate, blood pressure and urinary albumin-to-creatinine ratio at 21 years of age were similar in GH-treated young adults born SGA and untreated controls born SGA or AGA. We conclude that long-term GH treatment in children born SGA has no unfavourable effects on kidney function in early adulthood. PRÉCIS: We present a longitudinal study on kidney function in the follow-up of growth hormone-treated young adults who were born small for gestational age.

Physiologic Aspects of Pig Kidney Transplantation in Nonhuman Primates

Xenotransplantation can provide a solution to the current shortage of human organs for patients with terminal renal failure. The increasing availability of genetically engineered pigs, effective immunosuppressive therapy, and antiinflammatory therapy help to protect pig tissues from the primate immune response and can correct molecular incompatibilities. Life-supporting pig kidney xenografts have survived in NHP for more than 6 mo in the absence of markers of consumptive coagulopathy. However, few reports have focused on the physiologic aspects of life-supporting pig kidney xenografts. We have reviewed the literature regarding pig kidney xenotransplantation in NHP. The available data indicate (1) normal serum creatinine, (2) normal serum electrolytes, except for a trend toward increased calcium levels and a transient rise in phosphate followed by a fall to slightly subnormal values, (3) minimal or modest proteinuria without hypoalbuminemia (suggesting that previous reports of proteinuria likely were due to a low-grade immune response rather than physiologic incompatibilities), (4) possible discrepancies between pig erythropoietin and the primate erythropoietin receptor, and (5) significant early increase in kidney graft size, which might result from persistent effects of pig growth hormone. Further study is required regarding identification and investigation of physiologic incompatibilities. However, current evidence suggests that, in the absence of an immune response, a transplanted pig kidney likely would satisfactorily support a human patient.