Influence of growth hormone on cardiovascular health and disease

The relationship between morning blood pressure surge and serum IGF-1 level in acromegaly patients with hypertension

OBJECTIVE

High levels of insulin-like growth factor 1 (IGF-1) in patients with acromegaly cause structural and functional changes specific to the disease. These changes lead to mortality if the disease is not treated. Circadian blood pressure (BP) rhythm as measured by 24-h ambulatory blood pressure monitoring (ABPM) can change with a decrease in BP during sleep and a sudden increase in wakefulness.

AIM

We aim to evaluate the relationship between changes in BP and IGF-1 levels in patients with acromegaly.

METHODS

Patients who were diagnosed with acromegaly and the patient group with hypertension were included. Serum biochemistry parameters, serum IGF-1 level and ABPM follow-ups were compared in these patients.

RESULTS

In our study, 30 patients with acromegaly and 30 patients with hypertension without acromegaly were included. Thirty of the patients were male and 30 were female. There was a statistically significant difference between the groups in terms of IGF-1(p = < 0.001) and GH(p = 0.004). There was no significant difference between patients' office systolic/diastolic BP measurements, day/night, systolic/diastolic BP measurements and all systolic/diastolic BP measurements in ambulatory blood pressure follow-ups. There was a significant difference in morning blood pressure surge(p = < 0.001). A statistically significant difference was found between the acromegaly patient groups with MBPS below and above 25 mmHg in terms of IGF-1 (p = 0.025) and platelet levels (p = 0.004).

CONCLUSION

As a result, cardiovascular disease risks can be predicted in patients with high serum IGF-1 levels by planning ambulatory blood pressure in the early period.

Illicit use of androgens and other hormones: recent advances

PURPOSE OF REVIEW

To summarize recent advances in studies of illicit use of androgens and other hormones.

RECENT FINDINGS

Androgens and other appearance-enhancing and performance-enhancing substances are widely abused worldwide. Three notable clusters of findings have emerged in this field in recent years. First, studies almost unanimously find that androgen users engage in polypharmacy, often ingesting other hormones (e.g., human growth hormone, thyroid hormones, and insulin), ergo/thermogenic drugs (e.g., caffeine, ephedrine, and clenbuterol), and classical drugs of abuse (e.g., cannabis, opiates, and cocaine). Second, reports of long-term psychiatric and medical adverse effects of androgens continue to accumulate. In cardiovascular research particularly, controlled studies have begun to supersede anecdotal evidence, strengthening the case that androgens (possibly acting synergistically with other abused drugs) may cause significant morbidity and even mortality. Third, it is increasingly recognized that androgen use may lead to a dependence syndrome with both psychological and physiological origins. Androgen dependence likely affects some millions of individuals worldwide, and arguably represents the least studied major class of illicit drug dependence.

SUMMARY

Given mounting evidence of the adverse effects of androgens and associated polypharmacy, this topic will likely represent an expanding area of research and an issue of growing public health concern.

Association of circulating insulin-like growth factor 1 with hepatocellular carcinoma: one cross-sectional correlation study

Deregulation of insulin-like growth factor-1 (IGF-1) has been implicated in the pathogenesis of several malignancies. This study aimed to investigate the association of changes in circulating IGF-1 with hepatocellular carcinoma (HCC). The radioimmunoassay was used to analyze serum IGF-1 levels of 65 HCC patients and 165 healthy subjects. Serum IGF-1 levels were significantly decreased in the HCC patients as compared with the healthy subjects (158.46+/-105.07 vs. 247.63+/-149.96 ng/mL, P<0.001). Furthermore, insulin resistance was significantly higher in the HCC patients than the healthy subjects (P=0.027). In addition, the significant correlations of serum IGF-1 levels with age and insulin resistance in the healthy subjects were not noted in the HCC patients. Intriguingly, individuals with hepatitis C virus (HCV), not hepatitis B virus, had remarkably decreased IGF-1 levels in both groups of the HCC patients and healthy subjects. Moreover, in the HCV subgroup, serum IGF-1 levels were significantly reduced in the HCC patients than the healthy subjects (113.14+/-71.28 vs. 172.42+/-74.02 ng/mL, P=0.003). In conclusion, decreased serum IGF-1 levels were associated with HCC and the decrease was remarkably noted in those patients concomitant with chronic hepatitis C.

A case and review of acromegaly-induced cardiomyopathy and the relationship between growth hormone and heart failure: cause or cure or neither or both?

Growth hormone plays an integral role in the development and maintenance of structure and function of the heart. Specific involvement of the heart in acromegaly is termed acromegalic cardiomyopathy, manifested as concentric left ventricular hypertrophy and diastolic dys-function. Left untreated, it ultimately progresses to systolic heart failure. Heart failure from acromegalic cardiomyopathy is one of the most common causes of death in acromegaly. Current treatment options include different approaches to lower elevated growth hormone levels with improvement in symptoms, exercise tolerance, and echocardiographic improvement in regression of left ventricular hypertrophy and indices of diastolic dysfunction. On the other hand, growth hormone is essential for cardiac growth and function and exerts beneficial and protective effects on the cardiovascular system. Its potential role as adjunctive therapy in the treatment of heart failure as derived from experimental studies and clinical trials is discussed.

Recent insights into cardiac hypertrophy and left ventricular remodeling

Cardiac hypertrophy is a compensatory mechanism of the heart to maintain cardiac output under stresses that compromise cardiac function. Mechanical stretch and neurohumoral factors induce changes in intracellular signaling pathways resulting in increased protein synthesis and activation of specific genes promoting cardiac growth, eventually leading to left ventricular remodeling and cardiac dysfunction. The remodeling process results from alterations in cardiac myocytes as well as the extracellular matrix.