Can plasma antioxidants prevent DNA damage in oxidative stress condition induced by growth hormone deficiency? A pilot study

The Double-Edged Sword of Total Antioxidant Capacity: Clinical Significance and Personal Experience

Oxidative stress (OS) could be a condition underlying several human diseases, despite the physiological role of reactive oxygen species (oxidative eustress). Therefore, antioxidant compounds could represent a modulatory mechanism for maintaining a proper redox balance and redox signaling. When antioxidants are insufficient or overwhelmed, OS ensues, causing multiple damages at molecular, tissue, and cellular levels. This study focuses on the role of total antioxidant capacity (TAC) as a biomarker to be interpreted according to several clinical scenarios. After a brief description of various assay methods to elucidate terminology and physiopathological roles, we focus on the hormonal influence on TAC in blood plasma and other biological fluids, as different endocrine systems can modulate the antioxidant response. Furthermore, OS characterizes several endocrinopathies through different mechanisms: an inadequate antioxidant response to an increase in reducing equivalents (reductive distress) or a marked consumption of antioxidants (oxidative distress), which leads to low TAC values. An increased TAC could instead represent an adaptive mechanism, suggesting a situation of OS. Hence, the clinical context is fundamental for a correct interpretation of TAC. This review aims to provide the reader with a general overview of oxidative stress in several clinical examples of endocrine relevance, such as metabolic syndrome, non-thyroid illness syndrome, hypopituitarism, and infertility. Finally, the impact of dietary and surgical interventions on TAC in the model of metabolic syndrome is highlighted, along with personal experience.

Special features on insulin resistance, metabolic syndrome and vascular complications in hypopituitary patients

Pituitary hormone deficiency, hypopituitarism, is a dysfunction resulting from numerous etiologies, which can be complete or partial, and is therefore heterogeneous. This heterogeneity makes it difficult to interpret the results of scientific studies with these patients.Adequate treatment of etiologies and up-to-date hormone replacement have improved morbidity and mortality rates in patients with hypopituitarism. As GH replacement is not performed in a reasonable proportion of patients, especially in some countries, it is essential to understand the known consequences of GH replacement in each subgroup of patients with this heterogeneous dysfunction.In this review on hypopituitarism, we will address some particularities regarding insulin resistance, which is no longer common in these patients with hormone replacement therapy based on current guidelines, metabolic syndrome and its relationship with changes in BMI and body composition, and to vascular complications that need to be prevented taking into account the individual characteristics of each case to reduce mortality rates in these patients.

Beyond Growth Hormone: Association of Short Stature Types and Growth Hormones With Scoliosis

STUDY DESIGN

Cross-sectional and retrospective cohort study.

OBJECTIVE

We investigated the effect of 3 types of short stature [partial growth hormone deficiency (GHD), GHD, and idiopathic short stature (ISS)] and recombinant human growth hormone (rhGH) therapy on scoliosis.

SUMMARY OF BACKGROUND DATA

In short stature, rhGH is widely used and the concentration of growth hormone varies among types. The epidemiologic characteristics of scoliosis and the role of rhGH in scoliosis remain unclear.

PATIENTS AND METHODS

A cross-sectional study was conducted among 3896 patients with short stature (partial GHD, GHD, and ISS), and a 1:1 age and sex-matched control group with preexisting whole-spine radiographs. The cohort study included 2605 subjects who underwent radiography more than twice to assess scoliosis development, progression, and the need for bracing and surgery. Adjusted logistic regression was used to assess differences in the prevalence of scoliosis among patients with partial GHD, GHD, ISS, and controls. The Kaplan-Meier method was used to analyze the time course of scoliosis development and progression. Cox regression was applied to assess the independent factors related to scoliosis development and progression. Mendelian randomization analyses were also performed.

RESULTS

Compared with controls, patients with short stature had a higher incidence of scoliosis (34.47% in partial GHD, 31.85% in GHD, 32.94% in ISS vs . 8.83% in control, P < 0.001), a higher risk of scoliosis development [hazard ratio (HR) = 1.964 in partial GHD, P < 0.001; HR = 1.881 in GHD, P = 0.001; HR = 1.706 in ISS, P = 0.001), but not a higher risk of progression, brace, or surgery. Among the 3 types of short stature, there were no differences in the incidence, development, and progression of scoliosis or the need for bracing or surgery. RhGH treatment increased the risk of scoliosis development in each short-stature group (HR = 2.673 in partial GHD, P < 0.001; HR = 1.924 in GHD, P = 0.049; HR = 1.564 in ISS, P = 0.004). Vitamin D supplementation was protective against scoliosis development (HR = 0.456 in partial GHD, P = 0.003; HR = 0.42 in GHD, P = 0.013; HR = 0.838 in ISS, P = 0.257).

CONCLUSIONS

More attention should be paid to the spinal curve in patients with partial GHD, GHD, or ISS. For short stature treated with rhGH, the risk of scoliosis development was increased. Vitamin D supplementation may be beneficial for prevention.

LEVEL OF EVIDENCE

Level III.

Total Antioxidant Capacity: Biochemical Aspects and Clinical Significance

Despite the physiological role of oxidant molecules, oxidative stress (OS) could underlie several human diseases. When the levels of antioxidants are too low or too high, OS occurs, leading to damage at the molecular, tissue and cellular levels. Therefore, antioxidant compounds could represent a way to modulate OS and/or to maintain proper redox balance. This review provides an overview of the methods available to assess total antioxidant capacity (TAC) in biological systems to elucidate the correct terminology and the pathophysiological roles. The clinical context is fundamental to obtain a correct interpretation of TAC. Hence, we discuss metabolic syndrome and infertility, two clinical conditions that involve OS, including the potential prognostic role of TAC evaluation in monitoring antioxidant supplementation. This approach would provide more personalised and precise therapy.