PubMed · 5167111
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1971. Panel discussion. Hypophysectomy.. https://pubmed.ncbi.nlm.nih.gov/5167111/
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It has been shown that GH excess is associated with decreased leptin levels and decreased body fat mass. Reports regarding the effect of GH on serum leptin levels are inconsistent. We studied leptin secretion in 20 acromegalics before and 2 months after trans-sphenoidal surgery and in 20 gender-, age-, and body mass index (BMI)-matched control subjects. The mean 8-h leptin concentration for each subject was measured from a pool formed of samples collected hourly beginning at 2200 h until 0600 h the next morning. In a subgroup of 10 acromegalics, leptin pulsatility was assessed for the same period of time in 10-min sampling intervals. Basal GH, insulin-like growth factor-I (IGF-I), insulin, glucose, and lipids levels were measured. Area under the curve for insulin (AUCins) during oral glucose tolerance test was calculated. Control subjects and acromegalics had similar BMI, but patients with active acromegaly had significantly lower mean leptin level (mean +/- SEM; in men, 2.6+/-0.4 vs. 7.1+/-1.1 microg/L, P = 0.003; in women, 16.0+/-3.4 vs. 23.5+/-3.1 microg/L; P = 0.036). Mean 8-h leptin correlated with BMI (r = 0.57, P = 0.007, in controls; r = 0.70, P = 0.001, in patients). In stepwise regression analysis with mean 8-h leptin as a dependent variable, BMI (P<0.001) and gender (P = 0.01) in acromegalics entered the equation, whereas in control subjects gender, free fatty acids, insulin, and age accounted for 99.3% in leptin variability. After surgery, BMI did not change significantly; and glucose (P = 0.014), GH (P<0.001), and IGF-I (P<0.001) levels together with AUCins (P = 0.002) decreased, whereas mean leptin concentration rose significantly and attained normal levels (4.1+/-0.8 microg/L, P = 0.028) in acromegalic men and (23.6+/-4.7 microg/L, P = 0.003) in acromegalic women. Correlation between leptin level and BMI was preserved after surgery (r = 0.62, P = 0.005). In stepwise regression analysis, free fatty acids (P = 0.04) contributed to 26.8% of the variance in corrected-leptin (for BMI and gender). Leptin concentration peak height and interpeak nadir level rose significantly (P = 0.033 and P = 0.037) after surgery by Cluster analysis, without significant changes in leptin pulse frequency and incremental peak amplitude. Nocturnal rise of leptin (mathematically described by a cubic curve) was characterized by an acrophase just after midnight, before and after surgery. The amplitude and the average leptin concentration of the cubic fit increased significantly after surgery (P = 0.028 and P< 0.001). In conclusion in acromegalic patients: 1) leptin secretion maintains the pulsatility and nocturnal rise; 2) the gender-based leptin differences are preserved; 3) GH-IGF-I normalization leads to a rise in leptin that is not related to changes in BMI; and 4) the possible role of rise in leptin levels when assessing clinical and metabolic outcome of therapy in acromegalic patients deserves additional studies.
Pituitary adenomas result in clinical sequelae and accelerated mortality due to central mass effects or pituitary hormone hypersecretion and/or insufficiency. The low annual incidence and prolonged natural history of these rare tumors has hindered efforts to evaluate long-term clinical outcomes. Care of these patients is often provided by larger tertiary specialist referral centers. A novel evidence-based computerized pituitary tumor registry was developed to systematically evaluate epidemiological, biochemical, and clinical outcome data. Retrospective registration of 371 patients [99 clinically nonfunctioning tumors (CNFTs), 176 acromegalics, and 96 prolactinomas] with radiological, biochemical, and clinical evidence of pituitary tumors was performed. Analysis of this primarily specialist-referred population revealed a female predominance among CNFT (60%) and prolactinoma (69%) patients. Males had a significantly greater frequency of macroadenomas than females for CNFTs (92% vs. (68%) and for prolactinomas (74% vs. 40%). Males with prolactinomas also had higher mean pretreatment serum PRL levels (1206 vs. 219 ng/mL). Concurrent hyperprolactinemia was present in CNFT (47%) and acromegaly (33%) patients. Radiographic cure, defined as absence of visualized tumor, was achieved in 21% of CNFTs, 34% of acromegalies, and 21% of prolactinomas. Biochemical remission, defined by normalization of hormonal tumor markers, was observed in 35% of acromegaly and 39% of prolactinoma patients in the registry, thus reflecting the tertiary referral patterns. Nine premature deaths (patients aged < or =65 yr) occurred in the acromegaly subpopulation, whereas no premature deaths were encountered in nonacromegalic patients. In conclusion, this unique and comprehensive pituitary tumor registry enables identification of diagnostic and prognostic markers and evaluation of long-term clinical outcomes. Prospectively, this registry will improve therapeutic guidelines and cost-effective pituitary tumor management.