Administration of recombinant human growth hormone normalizes GH-IGF1 axis and improves malnutrition-related disorders in patients with anorexia nervosa

Exploring endocrinological pitfalls in pituitary surgery in the elderly

Background

Endoscopic transsphenoidal surgery (ETSS) is performed more frequently in elderly patients. We investigated endocrinological pitfalls in pituitary surgery in the elderly by a comparative study focusing only on elderly patients.

Methods

Ninety-nine elderly patients aged 65 years and over with non-functioning pituitary adenoma (NFPA) who underwent ETSS were retrospectively examined and classified into the early (aged 65-74 years) and late (aged 75 years and over) elderly groups. The baseline characteristics and anterior pituitary function were compared between the groups.

Results

Seventy patients were assigned to the early elderly group and 29 to the late elderly group. Thyroid-stimulating hormone (TSH) response in preoperative and postoperative thyrotropin-releasing hormone (TRH) tests revealed a significant difference between the groups. Preoperative and postoperative TSH responses were significantly correlated in both groups. Residual analysis of the correlation between preoperative free triiodothyronine (T3) secretion quantity and preoperative TSH response in both groups, which was significant, indicated that preoperative TSH response was significantly normal when preoperative free T3 secretion quantity was normal in the early elderly group, but preoperative free T3 secretion quantity was significantly lower regardless of preoperative TSH response in the late elderly group.

Conculsions

The present study suggested that preoperative and postoperative TSH secretory capacity was presumed to be normal when preoperative free T3 levels were normal in the early elderly patients with NFPA. On the other hand, TSH secretory capacity in the late elderly patients could only be assessed by the TRH test, which should be taken into account.

Retracted publications in the drug literature

Recent studies have suggested an increase in the number of retracted scientific publications. It is unclear how broadly the issue of misleading and fraudulent publications pertains to retractions of drug therapy studies. Therefore, we sought to determine the trends and factors associated with retracted publications in drug therapy literature. A PubMed search was conducted to identify retracted drug therapy articles published from 2000-2011. Articles were grouped according to reason for retraction, which was classified as scientific misconduct or error. Scientific misconduct was further divided into data fabrication, data falsification, questions of data veracity, unethical author conduct, and plagiarism. Error was defined as duplicate publication, scientific mistake, journal error, or unstated reasons. Additional data were extracted from the retracted articles, including type of article, funding source, author information, therapeutic area, and retraction issue. A total of 742 retractions were identified from 2000-2011 in the general biomedical literature, and 102 drug studies met our inclusion criteria. Of these, 73 articles (72%) were retracted for a reason classified as scientific misconduct, whereas 29 articles (28%) were retracted for error. Among the 73 articles classified as scientific misconduct, those classified as unethical author conduct (32 articles [44%]) and data fabrication (24 articles [33%]) constituted the majority. The median time from publication of the original article to retraction was 31 months (range 1-130). Fifty percent of retracted articles did not state a funding source, whereas pharmaceutical manufacturer funding accounted for only 13 articles (13%) analyzed. Many retractions were due to repeat offenses by a small number of authors, with nearly 40% of the retracted studies associated with two individuals. We found that a greater proportion of drug therapy articles were retracted for reasons of misconduct and fraud compared with other biomedical studies. It is important for health care practitioners to monitor the literature for retractions so that recommendations for drug therapy and patient management may be modified accordingly.

Disturbance of the growth hormone-insulin-like growth factor-1 axis associated with poor performance status in patients with solid tumors

OBJECTIVE

Hormonal imbalance characterized by excessive production of growth hormone (GH) and a low circulating concentration of insulin-like growth factor (IGF)-1 has been demonstrated in individuals with various serious conditions. However, little is known about changes in the GH-IGF-1 axis in cancer patients.

METHODS

We prospectively examined the circulating levels of several hormones in 58 patients with solid tumors who were classified according to Eastern Cooperative Oncology Group performance status (PS): PS 0-1, n = 15; PS 2, n = 15; PS 3, n = 15; and PS 4, n = 13. The relations of hormone concentrations, with a focus on the GH-IGF-1 system, to PS were evaluated by Spearman's rank correlation test and regression analysis.

RESULTS

The circulating levels of IGF-1, IGF-binding protein-3 and thyroid hormones (total T(3) and T(4)) were inversely correlated with PS score. The concentration of GH was increased irrespective of PS but not statistically significant. The ratio of IGF-I to GH was inversely correlated with PS. The levels of GH and IGF-1 in all patients were also inversely correlated.

CONCLUSIONS

The present study suggests that the GH-IGF-1 axis is disturbed in patients with cancer.

Effects of rhIGF-1 administration on surrogate markers of bone turnover in adolescents with anorexia nervosa

BACKGROUND

Adolescents with anorexia nervosa (AN) have low bone density and low levels of surrogate markers of bone formation. Low bone density is a consequence of hormonal alterations that include hypogonadism and decreases in IGF-1, a bone trophic factor. Although IGF-1 is key to pubertal bone accretion, and effects have been demonstrated in adults, there are no data regarding the effect of recombinant human (rh) IGF-1 administration in adolescents with AN.

OBJECTIVES

We hypothesized that rhIGF-1 would cause an increase in PINP, a bone formation marker, in girls with AN, without any effect on CTX, a bone resorption marker.

SUBJECTS AND METHODS

RhIGF-1 was administered at a dose of 30-40 mcg/k twice daily to 10 consecutive girls with AN 12-18 years old for 7-9 days. Ten age-matched girls with AN were followed without rhIGF-1 for a similar period. IGF-1, PINP and CTX levels were measured.

RESULTS

RhIGF-1 administration caused an increase in IGF-1 from day-1 to day-4/5 (p<0.0001) and day-1 to day-8/9 (p<0.0001). Simultaneously, PINP increased from day-1 to day-4/5 (p=0.004) and day-1 to day-8/9 (p=0.004), with a smaller increase from day-4/5 to day-8/9 (p=0.048). CTX levels did not change with rhIGF-1 administration. No changes occurred in IGF-1 or PINP levels in girls not receiving rhIGF-1; however, CTX levels increased significantly (p=0.01). Percent change in PINP was significantly higher (p=0.02) and percent change in CTX was significantly lower (p=0.006) in girls who received rhIGF-1 compared to those who did not receive any intervention. RhIGF-1 was well tolerated without hypoglycemia.

CONCLUSION

Short-term administration of rhIGF-1 causes an increase in a surrogate bone formation markers in girls with AN without significant side effects.