Poverty and immigration as a barrier to iodine intake and maternal adherence to iodine supplementation.

PURPOSE: Iodine deficiency still remains a significant health issue worldwide. Pregnant and lactating women are at risk for iodine deficiency when living in mild iodine-deficient areas such as Italy. This study aims at evaluating the consumption of iodized salt, iodine-rich-foods and maternal micronutrient supplements in a group of women with limited access to the Italian National Health System. METHODS: A cross-sectional survey was conducted among immigrant and Italian women living in poverty and referring to 40 Non-Governmental Organization throughout Italy for their health needs. 3483 women answered the ad hoc questionnaire between January 2017 and February 2018. RESULTS: The consumption of iodized salt was very low, and even lower among immigrant women. Determinants of iodized salt consumption were the period spent in Italy for immigrant women and living in a family-type setting, parity and, particularly, the degree of education for Italian ones. 17.5% of immigrant women and 8.6% of the Italian ones reported a diagnosis of thyroid disease. 521 women, 75.4% of whom were immigrants, were pregnant or breast-feeding. The majority (57.3%) had no specific maternal supplementation. CONCLUSIONS: Both Italian and immigrating women with a low income or without access to the public health system have a poor adherence both to the salt iodization policy and to folic acid and iodine supplements in preconception and pregnancy. They also referred a low-frequency intake of iodine-rich-foods. The identification of barriers to health care access could be useful to promote specific health interventions in this target population.

GH responsiveness before and after a 3-week multidisciplinary body weight reduction program associated with an incremental respiratory muscle endurance training in obese adolescents.

Several studies have demonstrated that the obesity-related hyposomatropism is usually reversible after a consistent weight loss induced by diet and/or bariatric surgery. Recently, a single bout of respiratory muscle endurance training (RMET) by means of a specific commercially available device (Spiro Tiger®) has been reported to induce a marked GH response in obese adults, its GH-releasing effect being significantly lower in obese adolescents. The GH response disappeared in both obese adults and adolescents when RMET was repeated at 2-h intervals in-between. The aim of the present study was to evaluate GH responses to repeated bouts of RMET administered before and after a 3-week in-hospital multidisciplinary body weight reduction program (entailing energy-restricted diet, 90 min/daily aerobic physical activity, psychological counseling, and nutritional education) combined with a progressively increasing RMET (15 daily sessions, 5 sessions per week) in 7 obese male adolescents [age: 12-17 years; body mass index (BMI): 38.5±3.1 kg/m2; percent fat mass (FM): 37.0±2.0%]. Blood samplings for GH determinations were collected during the 1st and 15th sessions, which were composed of 2 consecutive bouts of RMET (of identical intensity and duration) at 2-h interval in-between. At the beginning of the study, baseline GH levels significantly increased after the first bout of RMET in all subjects (p<0.05). The administration of the second bout of RMET resulted in a significantly lower (p<0.05) GH increase in comparison with the first one. Three weeks of the integrated intervention significantly reduced both body weight (from 115.3±9.2 kg to 111.5±8.7 kg, p<0.05) and FM (from 43.1±5.7 kg to 41.9±5.3 kg, p<0.05), these combined effects being, however, not sufficient to influence GH responsiveness to the 2 repeated bouts of RMET (GH peaks to the first bout: 4.8±1.6 ng/ml vs. 4.8±1.6 ng/ml; GH peaks to the second bout: 0.9±0.2 ng/ml vs. 1.1±0.1 ng/ml, before and after 3 weeks of the treatment, respectively, p=NS). In conclusion, a 3-week incremental RMET combined with a body weight reduction intervention does not seem useful to positively influence the reduced GH responsiveness to 2 repeated RMET bouts in obese adolescents. More intensive and/or long-term RMET protocols, associated with energy-restricted diets, determining more consistent changes in body composition, are likely needed to restore the impaired GH-IGF-1 function of obese adolescents.

GH responses to 2 consecutive bouts of respiratory muscle endurance training in obese adolescents and adults.

Repeated bouts of GH-releasing stimuli (both pharmacological and physiological, such as aerobic exercise) at 2-h intervals are associated with a blunting of somatotropic responsiveness in normal adults, while a persistent GH responsiveness to consecutive stimuli is reported to occur in children and adolescents. Recently, a single bout of respiratory muscle endurance training (RMET) by means of a specific commercially available device (Spiro Tiger®) has been shown to induce relevant GH responses in both normal-weighted and obese adult subjects. The aim of the present study was to evaluate GH responses to repeated bouts of RMET in obese adolescents and adults. Seven obese male adolescents (age: 15.7±0.4 years; body mass index, BMI: 38.0±3.3 kg/m2) and 10 obese adults (age: 22.2±1.4 years; BMI: 39.9±1.0 kg/m2) underwent an incremental progressive RMET protocol of 11 daily sessions. Blood samplings for GH determinations were collected during the 12th session, which was composed of 2 consecutive bouts of RMET (of identical intensity and duration: 1 min at a respiration rate of 28 acts/min, 5 min at 32 acts/min, 5 min at 34 acts/min, 4 min at 36 acts/min) at a 2-h interval in-between. Baseline GH levels significantly increased after the first bout of RMET in all subjects, higher GH peaks being found in obese adults than in obese adolescents (peaks: 14.3±2.1 ng/ml vs. 4.8±1.6 ng/ml, respectively, p<0.05). The administration of the second bout of RMET resulted in significantly lower (p<0.05) GH increases in both obese adolescents and obese adults (peaks: 0.9±0.2 ng/ml and 1.6±0.2 ng/ml, respectively) in comparison with the first one. In conclusion, exercise protocols based on repeated bouts of RMET do not seem a valid strategy to persistently stimulate GH-IGF-1 release in obese adolescents, since GH responses to a single bout are actually modest in comparison with those of obese adults and completely abolished after repeated bouts at 2 h interval in-between.

GH and cortisol responses following an acute session of respiratory muscle endurance training in severely obese patients.

It is well established that obese patients are hypo-responsive to classical GH-releasing stimuli, including aerobic exercise. Recently, we have demonstrated that whole body vibration was able to markedly stimulate GH secretion in obese patients, thus suggesting that this refractoriness is not absolute but dependent on the GH-releasing stimulus. Furthermore, we have shown the ability of a respiratory muscle endurance training (RMET) to stimulate GH and cortisol secretion in healthy subjects. The objective of this study was to evaluate the effects of RMET on GH and cortisol responses in severely obese patients. Eight severely obese patients (4 M/4 F, mean age±SEM: 22.8±1.6 years, body mass index, BMI: 39.9±1.1 kg/m2) underwent an incremental progressive RMET protocol of 11 daily sessions, obtained through the use of a specifically designed respiratory device (Spiro Tiger®). The 12th session of RMET (15 min duration: 1 min at a respiration rate of 28 acts/min, 5 min at 32 acts/min, 5 min at 34 acts/min, 4 min at 36 acts/min) was associated with blood samplings for determination of GH, cortisol, and lactate (LA) levels. An age- and sex-matched normal-weighted control group (n=7, 4 M/3 F, age: 26.1±3.1 years, BMI: 22.4±0.6 kg/m2) was also recruited. In both normal-weighted subjects and obese patients, GH secretion significantly increased after a 15-min RMET session. Although serum GH levels at 30 min were higher in normal-weighted subjects than in obese patients, there was no statistically significant difference in either GH peaks or net GH areas under the curve between the 2 groups. RMET significantly increased serum cortisol levels in normal-weighted subjects, but was associated to a progressive cortisol decline in obese patients. RMET stimulated LA production, with no significant differences in normal-weighted subjects and in obese patients. A 15-min RMET session was capable to induce a GH response in severely obese patients, which was comparable to that recorded in normal-weighted subjects. A progressive decline in serum cortisol levels occurred in obese patients after RMET, while an opposite pattern (i. e., a significant cortisol increase) was found in normal-weighted subjects. Optimization of long-term RMET protocols could represent a valid strategy to (physiologically) stimulate GH/IGF-I system in those GH hyposecretory states such as obesity.

GH responses to two consecutive bouts of respiratory muscle endurance training in healthy adults.

Repetition of voluntary exercise bouts and of different pharmacological GH-releasing stimuli at 2-h intervals is associated with a complete abolishment of GH responsiveness. By contrast, a different pattern is observed after repeated neuromuscular electrostimulation, which is characterized by preservation of GH responsiveness. Aim of the study was to evaluate GH responses to repeated bouts of respiratory muscle endurance training (RMET) by mean of a specific commercially available device (Spiro Tiger®). Eight healthy men underwent an incremental progressive RMET protocol of 11 daily sessions. Blood samplings for GH, cortisol and lactate (LA) determinations were collected during the 12th session, which was composed of two consecutive bouts of RMET (of identical intensity and duration: 1 min at a respiration rate of 28 acts/min, 5 min at 32 acts/min, 5 min at 34 acts/min, 4 min at 36 acts/min) at a 2 h interval. Baseline GH levels (mean: 0.9±0.4 ng/ml) significantly (p<0.01) increased after the first bout of RMET (peak: 15.7±4.0 ng/ml). The administration of the second bout of RMET resulted in a significantly lower (p<0.05) GH increase (peak: 3.9±0.8 ng/ml) in comparison with the first one. Baseline LA levels (mean: 1.2±0.1 mmol/l) significantly increased (p<0.001) after the first bout of RMET (peak: 2.3±0.2 mmol/l). The administration of the second RMET bout resulted in a comparable LA increase (from a basal value of 1.2±0.1 mmol/l up to a peak of 2.0±0.1 mmol/l, p<0.001). The first bout of RMET caused a significant increase of cortisol levels (p<0.01), starting from a basal mean value of 142.9±9.4 ng/ml up to a peak of 188.8±10.3 ng/ml. By contrast, the second bout of RMET did not induce any significant change of cortisol levels (basal: 149.1±9.0 ng/ml, peak: 168.5±5.1 ng/ml). In conclusion, a single bout of RMET is capable of stimulating GH and cortisol secretions and LA production. When a second bout is repeated after 2 h, there is a blunting of GH and cortisol responses with a preservation of LA release. Further studies are needed to schedule long-term RMET protocols capable of persistently stimulating GH-IGF-I release and to maximally enhance the ergogenic and metabolic benefits of this intervention either in normal subjects (e.g. athletes) or patients with an impairment of motor capabilities requested to perform normal daily activities (i.e. severely obese and elderly people).

Growth hormone response induced by a respiratory muscle endurance training in healthy subjects.

To date, the large majority of studies evaluating growth hormone (GH) response to acute physical exercise has been performed involving gross muscle groups. To the best of our knowledge, none has evaluated the effects of a respiratory muscle endurance training (RMET) on hormonal secretions, particularly on GH release, though some respiratory devices have been widely used in athletes to train respiratory muscles and to improve cardiopulmonary function and physical performance. 8 healthy men underwent an incremental progressive RMET protocol of 11 daily sessions, obtained through the use of a specifically designed respiratory device (Spiro Tiger®). The 12th session of RMET (15 min duration: 1 min at a respiration rate of 28 acts/min, 5 min at 32 acts/min, 5 min at 34 acts/min, 4 min at 36 acts/min) was associated with blood samplings for determination of GH, cortisol, ghrelin, glucose, and lactate (LA) levels. GH and cortisol responses significantly increased after a 15-minute RMET session, which, in contrast, inhibited ghrelin secretion. There was a minimal, though significant, increase in LA levels with a significant elevation in glycemia. A 15-minute RMET session, administered after a 11-days incremental progressive RMET protocol, was capable of stimulating GH and cortisol release and suppressing ghrelin secretion. Optimization of incremental progressive RMET protocols would be important to maximize the positive chronic effects of this intervention on somatotropic function and muscle performance.

Defective hypothalamic growth hormone (GH)-releasing hormone activity may contribute to declining GH secretion with age in man.

There is evidence that withdrawal of SRIH infusion in man promotes a rebound GH response that allegedly has been proposed to be related to the function of GHRH-producing neurons. In the present study we have evaluated whether a reduction in endogenous GHRH activity contributes to the decreased GH secretion of the elderly. Sixteen young (8 women, aged 23-32 yr, and 8 men, aged 18-27 yr) and 13 elderly (8 women, aged 65-82 yr, and 5 men, aged 65-70 yr) healthy subjects volunteered to participate in this investigation. Each subject was tested on 2 separate occasions: 1) a 90-min iv infusion of SRIH was given in 50 mL 0.9% saline delivered at a rate of 9 micrograms/kg.h; and 2) a 90-min iv infusion of isovolumetric amounts of 0.9% saline was given. Plasma GH levels were determined before and up to 180 min after SRIH or saline infusion, whereas plasma insulin-like growth factor I, estradiol, and testosterone levels were measured in basal samples. In elderly women, the mean maximum (delta) GH peak (2 +/- 0.7 micrograms/L) after withdrawal of SRIH infusion was significantly (P < 0.02) lower than that in young women (7.3 +/- 2 micrograms/L). In elderly men, the mean delta GH peak (2.9 +/- 0.6 micrograms/L) after withdrawal of SRIH infusion was lower than that in young men (6.3 +/- 1.6 micrograms/L), although the difference failed to achieve statistical significance. Baseline insulin-like growth factor I levels were significantly lower in elderly compared to young subjects in both men and in women. In women, both age and basal plasma estradiol and testosterone levels significantly correlated with delta GH peak after SRIH withdrawal (r = -0.61, r = 0.61, and r = 0.66, respectively), whereas in men they did not. These findings are compatible with the view that an age-related decrease in endogenous GHRH function may contribute to the defective GH secretion of the elderly. Alterations in plasma concentrations of sex steroids may have important implications in the observed changes.