Elevated circulating somatostatin levels in acromegaly

Effects of calorie intake and sampling time on thyroid stimulating hormone concentration

BACKGROUND

This study aimed to investigate the effects of blood sampling after calorie intake on thyroid stimulating hormone (TSH) level, compared with blood sampling in fasting state.

METHODS

This was a prospective, randomized, controlled study. Subjects from the outpatients in the department of endocrinology without evidence of thyroid diseases were included and then randomized into the fasting group, diet intake group, and glucose intake group, respectively. Fasting blood was collected from all subjects at 7:00 am for the measurement of TSH and free thyroxine (FT₄) concentrations. Afterwards, the subjects were maintained at fasting state (fasting group), had an intake of the mixed diet with 400 kcal calories (diet intake group), and had an intake of 75 g glucose (glucose intake group), respectively, and blood was collected again 2 h later (9:00 am on the same day) for TSH and FT₄ level measurement and comparison.

RESULTS

A total of 150 subjects were enrolled, of whom 146 met the inclusion criteria, with 48, 48, and 50 in the diet intake group, glucose intake group, and fasting group, respectively. The TSH in the diet intake group was significantly lower at 9:00 am (TSH_9am) than the level at 7:00 am (TSH_7am) (P < 0.001), with a median variation of -0.71 mU/L, and a median variation rate of -32.4%. In the glucose intake group, TSH_9am was also significantly lower than TSH_7am (P < 0.001), with a median variation of -0.73 mU/L, and a median variation rate of -31.5%. For the fasting group, TSH_9am decreased slightly but was significantly lower than TSH_7am (P < 0.001), with a median variation of -0.1 mU/L, and a median variation rate of -5.2%. According to TSH_7am measurements, 9 subjects (3 subjects in each group) met the diagnostic criteria of subclinical hypothyroidism. However, according toTSH_9am measurements, only 2 patients in the fasting group met the diagnostic criteria of subclinical hypothyroidism.

CONCLUSION

Compared with the fasting state, the TSH level at 2 h after the calorie intake was decreased by about 30%, which might influence the diagnosis of subclinical hypothyroidism.

TRIAL REGISTRATION

ChiCTR2100047454 (18/06/2021).

LONGER CECUM INSERTION TIME AND MORE INADEQUATE COLONIC PREPARATION IN PATIENTS WITH ACROMEGALY: IS A DIFFERENT COLONOSCOPY PREPARATION NEEDED?

Purpose

To investigate whether there is a difference between acromegalic and non-acromegalic cases in terms of bowel preparation and colonoscopic intervention.

Methods

Patients with controlled and uncontrolled acromegaly and as a control group (CG) patients without acromegaly between January 2010 and March 2014 were included. Groups were compared regarding adequacy of bowel preparation, cecal insertion time (CIT) and colonoscopy results.

Results

Fifty-nine patients with acromegaly (controlled n=30, uncontrolled n=29) and 73 age and gender matched volunteers without acromegaly were evaluated. CIT in cases with controlled, uncontrolled acromegaly cases and in CG was 5.33 [4.00-6.00], 7.00 [4.91-11.31], and 3.10 [2.35-4.65] minutes, respectively (p<0.001). Cases in CG had shorter CIT compared to controlled and uncontrolled acromegaly cases ( p=0.014 and p<0.001, respectively). There was no significant difference regarding CIT between controlled and uncontrolled acromegaly cases (p=0.247). Six (20%) of controlled acromegaly patients, 10 (35%) of uncontrolled acromegaly patients and three (4%) of CG had inadequate bowel cleansing (p<0.001). Although statistically insignificant, cases with inadequate bowel cleansing had tendency towards having prolonged CIT in comparison to cases with adequate bowel cleansing (6.00 [3.87-9.00] and 4.16 [2.95-5.70] minutes, respectively, p=0.07).

Conclusion

Inadequate bowel cleansing is one of the main problems encountered during colonoscopic investigation/surveillance in acromegalic patients. Therefore, a different protocol for colonoscopy preparation may be needed for these cases.

N-Terminal Prosomatostatin as a Risk Marker for Cardiovascular Disease and Diabetes in a General Population

CONTEXT

Somatostatin inhibits a range of hormones, including GH, insulin, and glucagon, but little is known about its role in the development of cardiometabolic disease.

OBJECTIVE

The objective of the study was to investigate whether fasting plasma concentration of N-terminal prosomatostatin (NT-proSST) is associated with the development of diabetes, coronary artery disease (CAD), and mortality.

DESIGN, SETTING, AND PARTICIPANTS

NT-proSST was measured in plasma from 5389 fasting participants of the population-based study Malmö Preventive Project, with a mean baseline age of 69.4 ± 6.2 years. Cox proportional hazards models adjusted for traditional cardiovascular risk factors were used to investigate the relationships between baseline NT-proSST and end points, with a mean follow-up of 5.6 ± 1.4 years.

MAIN OUTCOME MEASURES

CAD, diabetes, and mortality were measured.

RESULTS

Overall, NT-proSST (hazard ratio [HR] per SD increment of log transformed NT-proSST) was unrelated to the risk of incident diabetes (220 events; HR 1.05; 95% confidence interval [CI] 0.91-1.20; P = .531) but was related to the risk of incident CAD (370 events; HR 1.17; 95% CI 1.06-1.30; P = .003), all-cause mortality (756 events; HR 1.24; 95% CI 1.15-1.33; P < .001), and cardiovascular mortality (283 events; HR 1.33; 95% CI 1.19-1.43; P < .001). The relationships were not linear, with most of the excess risk observed in subjects with high values of NT-proSST. Subjects in the top vs bottom decile had a severely increased risk of incident CAD (HR 2.41; 95% CI 1.45-4.01; P < .001), all-cause mortality (HR 1.84; 95% CI 1.33-2.53; P < .001), and cardiovascular mortality (HR 2.44; 95% CI 1.39-4.27; P < .001).

CONCLUSION

NT-proSST was significantly and independently associated with the development of CAD, all-cause mortality, and cardiovascular mortality.

Analysis of somatostatin receptors 2 and 5 polymorphisms in patients with acromegaly

OBJECTIVE

The aim of the study was to investigate the possible correlation of single nucleotide polymorphisms in somatostatin receptor (SSTR)2 and SSTR5 genes with the responsiveness to somatostatin analogs in a cohort of acromegalic patients.

STUDY DESIGN

Three single nucleotide polymorphisms (a-83 g, c-57 g, and t80c) of SSTR2 and three (t-461c, c325t, and c1004t) of SSTR5 were analyzed in 66 acromegalic patients with different responsiveness to somatostatin analogs and 66 healthy controls.

RESULTS

Allele frequencies in patients and controls were similar. No association between SSTR2 genotypes and GH and IGF-I levels was found. When considering SSTR5 variants, patients homozygous or heterozygous for the substitution c1004 (P+) showed basal IGF-I levels significantly lower than patients homozygous for 1004t (P-). Moreover, serum GH levels were lower in patients with P+/T- haplotype (having c1004 allele and no t-461 allele) than in those with P-/T+. No correlation between SSTR2 and SSTR5 genotypes, responsiveness to somatostatin therapy, and mRNA expression in the removed adenomas (n = 10) was found.

CONCLUSIONS

These data suggest a role for SSTR5 t-461c and c1004t alleles in influencing GH and IGF-I levels in patients with acromegaly, whereas SSTR2 and SSTR5 variants seem to have a minor role in determining the responsiveness to somatostatin analogs.