Unexpected evolution of a monster case of insulin-induced skin lipohypertrophy

In this journal, in 2020, we published the case of a 74-year-old female outpatient with type-2 diabetes mellitus who self-injected insulin four times a day according to the basal-bolus regimen, with an high glycemic variability and an high rate of severe hypoglycemic episodes. Three years before, we had found two extraordinarily large skin lipohypertrophies, with large underlying fluid collections with high insulin concentration. A long educational and intensive training completely repaired the skin lesions with the disappearance of the subcutaneous insulin reservoirs. Glycemic variability has been reduced dramatically, severe hypoglycemia has almost completely disappeared and the daily dose of insulin has been reduced by 38%. However, this extraordinary, albeit unexpected, result was achieved in five years.

The gut microbiome as possible mediator of the beneficial effects of very low calorie ketogenic diet on type 2 diabetes and obesity: a narrative review

Several studies have shown a strong correlation between the different types of diets and gut microbiota composition on glycemia and weight loss. In this direction, low-carbohydrate and ketogenic diets have gained popularity, despite studies published so far leading to controversial results on subjects with diabetes. In this narrative review, firstly, we aimed to analyze the role of very-low-calorie ketogenic diets (VLCKDs) in type 2 diabetes (T2DM) and obesity management. Secondly, in this context, we focused attention on gut microbiota as a function of VLCKD, particularly in T2DM and obesity treatment. Finally, we reported all this evidence to underline the importance of gut microbiota to exalt new nutritional strategies for "tailor-made" management, treatment, and rehabilitation in subjects with T2DM and obesity, even with diabetic complications. In conclusion, this narrative review outlined the beneficial impact of VLCKD on gut microbiota even in subjects with T2DM and obesity, and, despite inner VLCKD short-duration feature allowing no sound-enough provisions for long-term outcomes, witnessed in favor of the short-term safety of VLCKD in those patients.Level of evidence Level V: Opinions of authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

Space Flight-Promoted Insulin Resistance as a Possible Disruptor of Wound Healing

During space flight, especially when prolonged, exposure to microgravity results in a number of pathophysiological changes such as bone loss, muscle atrophy, cardiovascular and metabolic changes and impaired wound healing, among others. Interestingly, chronic low-grade inflammation and insulin resistance appear to be pivotal events linking many of them. Interestingly, real and experimental microgravity is also associated to altered wound repair, a process that is becoming increasingly important in view of prolonged space flights. The association of insulin resistance and wound healing impairment may be hypothesized from some dysmetabolic conditions, like the metabolic syndrome, type 2 diabetes mellitus and abdominal/visceral obesity, where derangement of glucose and lipid metabolism, greater low-grade inflammation, altered adipokine secretion and adipocyte dysfunction converge to produce systemic effects that also negatively involve wound healing. Indeed, wound healing impairment after traumatic events and surgery in space remains a relevant concern for space agencies. Further studies are required to clarify the molecular connection between insulin resistance and wound healing during space flight, addressing the ability of physical, endocrine/metabolic, and pharmacological countermeasures, as well as nutritional strategies to prevent long-term detrimental effects on tissue repair linked to insulin resistance. Based on these considerations, this paper discusses the pathophysiological links between microgravity-associated insulin resistance and impaired wound healing.

Policaptil Gel Retard in adult subjects with the metabolic syndrome: Efficacy, safety, and tolerability compared to metformin

BACKGROUND

Policaptil Gel Retard® (PGR), is a new macromolecule complex based on polysaccharides slowing the rate of carbohydrate and fat absorption. It proved to significantly reduce body weight, acanthosis nigricans expression, HbA1c levels, and glucose metabolism abnormalities in obese, hyper-insulinemic adolescents. No such data are available for adults.

AIM

to compare the effects of PGR vs. metformin in adult subjects with the Metabolic Syndrome (MS) and T2DM on a Low Glycemic Index diet.

SUBJECTS AND METHODS

This spontaneous clinical, longitudinal, single-blind, randomized study based on a per-protocol analysis enrolled 100 outpatients with MS and T2DM consecutively referring to our clinic for three months, and randomly assigned to either the active treatment (Group A:, 6 tablets/day) or the comparator (Group B: Metformin tablets, 1500-2000 mg/day in two divided doses during the two main meals, to minimize side effects) to be taken 30 min before each main meal in equally divided doses. Serum lipid profile, anthropometry, HOMA-IR index, and tolerability parameters were evaluated before and after a 6-month follow-up period.

RESULTS

all parameters improved at a similar rate in both groups but for the lipid profile, which got even better in Group A. Group A also experienced less prominent gastrointestinal side effects than its counterpart.

CONCLUSION

For the first time, we showed the non-inferiority of PGR compared to metformin in obese adult subjects with the MS and T2DM as for glycemic control and a clear-cut superiority of PGR in terms of both serum lipid-lowering capacity and tolerability.

Technological innovation of Continuous Glucose Monitoring (CGM) as a tool for commercial aviation pilots with insulin-treated diabetes and stakeholders/regulators: A new chance to improve the directives?

Civil aviation pilots who develop insulin-treated diabetes and want to renew a Commercial Pilot License (CPL) represent a medical, social and regulatory problem. This depends on justified concerns about hypoglycemia, the most threatening event for people who carry out jobs requiring a high level of concentration and reliability. This negatively affects social and working aspects of pilots' lives, who have a high profile and a high-cost professional qualification. It could be possible now to revise this attitude thanks to the availability of Continuous Glucose Monitoring (CGM) devices. CGM clearly showed to prevent hypoglycemic events in insulin-treated diabetic patients by allowing strict monitoring and trend prediction of glucose levels. By systematizing available data on such devices and present regulations in CPL issuance worldwide, our review can be used as handy tool for a fruitful discussion among the scientific community, national and international civil aviation regulators, stakeholders and pilots, aimed at evaluating the evidence-based opportunity to revise CPL issuance criteria for insulin-treated diabetic pilots. For the above-mentioned reasons, there are, among the regulatory administrations of Civil Aviation around the globe, several different approaches and limitations set for the subjects with insulin-treated diabetes who want to obtain, or renew, a CPL.

HOW to make a mix of low glycemic index flours for a good Neapolitan pizza for patients with diabetes

BACKGROUND AND AIMS

Our recent data document that a low glycemic index (LGI) Neapolitan pizza prepared with a mix of Kamut and whole wheat flours plus Glucomannan, (i) has a lower impact on postprandial hyperglycemic spikes than pizza made of whole wheat flour, (ii) is pleasant and appreciated as traditional one and (iii) does not cause any gastro-intestinal troubles. The aim of our study was to describe the validation process underlying the identification of the right mix of those elements for a LGI pizza preventing gastro-intestinal disturbances.

METHODS

we described all procedures followed to make good products with different combinations of the three components and a series of tests made by four well-experienced professional pasta-making masters, one nutritionist, five diabetologists, one nurse and twenty volunteers with T1DM.

RESULTS

we could identify the best workable and most suitable flour mix to achieve both pleasant taste and low glycemic impact proving to be efficient in real-life twin paper providing results from diabetic patients.

CONCLUSIONS

this kind of food will certainly help people with diabetes eat pizza without risking any serious deterioration of their own glucose control while fully enjoying socially active life.

Is pizza sutable to type 1 diabetes? A real life identification of best compromise between taste and low glycemic index in patients on insulin pump

Opposed to whole wheat (WWP), traditional pizza (TP) is loved by patients with type 1 diabetes mellitus (T1DM) despite causing hyperglycemia. 50 well-trained T1DM patients had higher glucose levels after TP than after WWP or mixed flour pizza, which however was tasty, digestible and metabolically appropriate to break diet monotony.

Insulin-induced lypodistrophy in hemodialyzed patients: A new challenge for nephrologists?

Diabetes Mellitus (DM) is the most common cause of renal failure and ESRD all over the world, and often requires an individualized insulin treatment regimen. Malnutrition, depression-related eating behavior changes, high on-off-dialysis day-to-day glycemic variability and frequent hypoglycemic events occurring during or immediately after dialysis make it hard to identify best insulin dosage in hemodialyzed patients. This suggests a prudent attitude including non-stringent control, despite which repeated hypoglycemia quite often occurs in such patients. When looking for possible sources of hypoglycemia, health professionals too often overlook the identification of skin lipodystrophy (LD) due to an incorrect insulin injection technique. This mini-review focuses on the high frequency (57%) of LD in a cohort of 1004 insulin-treated people with DM on dialysis consecutively referring to our joint medical centers, and on its relationship with hypoglycemia and glycemic control/variability. When taking on such patients, care team members accept to face a complex disease burdened with several risk factors requiring high professional skills, and have to keep in mind also the possible presence of any LD areas eventually interfering with expected results. A timely educational intervention on the correct injection technique can help reduce the high risk of hypoglycemia and large glycemic variability in dialysed people with DM.

Lessons learned from an unusual case of severe hypoglycemia

We are hereby reporting on a woman with type 1 diabetes getting insulin, 4 shots a day, and referring to us for an episode of severe hypoglycemia occurred after vigorously rubbing a lipo-hypertrophy (LH). She had always injected insulin into an abdominal LH area but had never suffered from any hypoglycemic event (Hypo) during the last period. Nevertheless her history included frequent Hypos, mostly mild-to-moderate but sometimes severe and eventually ending into unconsciousness and her glycemic control was poor (HbA1c 8.3%, mean FPG 161 ± 22 mg/dl, mean PPG 218 ± 51 mg/dl, glycemic variability (106 ± 44 mg/dl). In fact, all of a sudden she rubbed vigorously the LH area trying to get rid of the abdominal skin thickening and soon after a severe Hypo occurred causing her to need for emergency medical assistance. When back at home, she corrected her technique and carefully refrained from inject insulin into the LH so that after six months the lesion disappeared, glycemic control improved and no Hypo occurred any more. Based on the recent publication reporting on a woman with a large LH consisting of thickened skin surrounding some fluid containing insulin at concentrations 13 fold those in blood, we hypothesize that such severe depended on massive insulin release from rubbed skin stores into the blood stream.

Why are so huge differences reported in the occurrence rate of skin lipohypertrophy? Does it depend on method defects or on lack of interest?

Lipohypertophy (LH) is the most common skin complication of incorrect injection technique which does not only represent an aesthetic defect but also severely disrupts insulin pharmacokinetics/pharmacodynamics. As a consequence of that, hormone release is delayed and unexplained/unpredictable hypoglycemia occurs, both deteriorating metabolic control while negatively affecting adherence to treatment and quality of life. The economic burden due to unwanted intra-LH injections is accounted for by inappropriately high insulin requirements, increased emergency-related hospitalizations, and loss of work days. Greater attention has to be paid by diabetes care teams to education programs with periodic refreshers to achieve better metabolic control and reduce the economic burden of diabetes.

Body composition and metabolic changes during a 520-day mission simulation to Mars

PURPOSE

The "Mars-500 project" allowed to evaluate the changes in psychological/physiological adaptation over a prolonged confinement, in order to gather information for future missions. Here, we evaluated the impact of confinement and isolation on body composition, glucose metabolism/insulin resistance and adipokine levels.

METHODS

The "Mars-500 project" consisted of 520 consecutive days of confinement from June 3, 2010 to Nov 4, 2011. The crew was composed of six male subjects (three Russians, two Europeans, and one Chinese) with a median age of 31 years (range 27-38 years).

RESULTS

During the 520-day confinement, total body mass and BMI progressively decreased, reaching a significant difference at the end (417 days) of the observation period (- 9.2 and - 5.5%, respectively). Fat mass remained unchanged. A progressive and significant increase of fasting plasma glucose was observed between 249 and 417 days (+ 10/+ 17% vs baseline), with a further increase at the end of confinement (up to + 30%). Median plasma insulin showed a non-significant early increment (60 days; + 86%). Total adiponectin halved (- 47%) 60 days after hatch closure, remaining at this nadir (- 51%) level for a further 60 days. High molecular weight adiponectin remained significantly lower from 60 to 168 days.

CONCLUSIONS

Based on these data, countermeasures may be envisioned to balance the potentially harmful effects of prolonged confinement, including a better exercise program, with accurate monitoring of (1) the individual activity and (2) the relationship between body composition and metabolic derangement.

Skin complications of insulin injections: A case presentation and a possible explanation of hypoglycaemia

We are willing to report the case of a woman with type 2 diabetes treated with insulin, 4 shots a day, referring to us for 2 very large pigmented abdominal lipo-hypertrophy (LH) areas due to incorrect injection technique. The ultrasound examination showed the presence offluidwithin both LH lesions. Fluid examination showed insulin concentrations 13 times higher thancirculating ones. A12-month longstructured training on correct injection techniques normalized metabolic control and took rid of all sudden severe hypoglycemic episodes and the wide glycemic variability. In fact, both LH areas disappeared became softer and slightly smaller and got fluid-free. This is the first case documenting the presence of sort of an insulin reservoir within LH lesions and fluid reabsorption can explain the disappearance of hypoglycemic episodes and the improvement of glycemic control.

Bioimpedance analysis, metabolic effects and safety of the association Berberis aristata/Bilybum marianum: a 52-week double-blind, placebo-controlled study in obese patients with type 2 diabetes

Berberine, a quaternary isoquinoline alkaloid present in Berberis aristata, is well known in terms of cholesterol-lowering, hypoglycemic, and insulin sensitizing effects. Because of its low oral bioavailability, to improve intestinal absorption it has been recently combined with silymarin (Silybum marianum). The aim of our placebo controlled study was to evaluate the effects of its association with silymarin on abdominal fat in overweight/obese patients with type 2 diabetes mellitus (T2DM). To do so, 136 obese subjects with T2DM and metabolic syndrome were analyzed for fasting blood glucose and insulin, Insulin Resistance index according to the Homeostatic Model Assessment (HOMA-R), total, HDL and LDL cholesterol, triglycerides, uric acid, BMI, waist circumference, waist to hip ratio and underwent bioelectrical impedance to assess % of abdominal fat. All the above-mentioned parameters, as recorded at enrollment, after 6 months and at the end of the study, had significantly improved in the BBR-treated group in respect to baseline and to the control group. A validated national cardiovascular risk score also improved significantly after BBR treatment in respect to placebo. Our results point to a clinically significant effect in obese people with T2DM and metabolic syndrome. Moreover, for the first time, they provide evidence of a significant uric acid lowering activity as an additive beneficial effect of the association BBR + silymarin.

Lispro insulin in people with non-alcoholic liver cirrhosis and type 2 diabetes mellitus

AIMS

To compare metabolic control under lispro and recombinant regular human insulin (RHI) in people with diet-unresponsive type 2 diabetes mellitus (T2DM) and compensated non-alcoholic liver disease (CLD).

METHODS

108 people with T2DM and CLD were randomly allocated to RHI or lispro according to a 12+12 week cross-over protocol. A 1-week continuous glucose monitoring (CGM) session was performed at the end of each treatment period followed by a standard meal test with a 12IU lispro or RHI shot ahead.

RESULTS

CGM showed higher glycemic excursions under RHI than under lispro (p<0.01) with lower glucose levels in the late post-absorption phase (p<0.05) and even more during the night (p<0.01). Post-challenge incremental areas under the curve (ΔAUC) were undistinguishable for insulin but lower for glucose, while insulin peaked higher and earlier and glycemic excursions were lower with lispro than with RHI (0.05<p<0.001).

CONCLUSIONS

Lispro granted lower early postprandial glucose levels and late postprandial hypoglycemic rates and therefore might represent the treatment of choice for people with T2DM and compensated CLD. This might depend on its faster/shorter-living effects, as well as, on the lower liver glucose output expected from its earlier hepatic distribution.

Stage of change and motivation to healthy diet and habitual physical activity in type 2 diabetes

Lifestyle changes to healthy diet (HD) and habitual physical activity (HPA) are recommended in type 2 diabetes mellitus (T2DM). Yet, for most people with diabetes, it may be difficult to start changing. We investigated the stage of change toward healthier lifestyles according to Prochaska's model, and the associated psychological factors in T2DM patients, as a prerequisite to improve strategies to implement behavior changes in the population. A total of 1,353 consecutive outpatients with T2DM attending 14 tertiary centers for diabetes treatment completed the validated EMME-3 questionnaire, consisting of two parallel sets of instruments to define the stage of change for HD and HPA, respectively. Logistic regression was used to determine the factors associated with stages that may hinder behavioral changes. A stage of change favoring progress to healthier behaviors was more common in the area of HD than in HPA, with higher scores in action and maintenance. Differences were observed in relation to gender, age and duration of disease. After adjustment for confounders, resistance to change toward HD was associated with higher body mass index (BMI) (odds ratio (OR) 1.05; 95 % confidence interval (CI) 1.02-1.08). Resistance to improve HPA also increased with BMI (OR 1.06; 95 % CI 1.03-1.10) and decreased with education level (OR 0.74; 95 % CI 0.64-0.92). Changing lifestyle, particularly in the area of HPA, is not perceived as an essential part of treatment by many subjects with T2DM. This evidence must be considered when planning behavioral programs, and specific interventions are needed to promote adherence to HPA.

Free Triiodothyronine and Cholesterol Levels in Euthyroid Elderly T2DM Patients

Thyroid function regulates lipid metabolism. Despite the fact that T2DM is more prevalent in the elderly, often associates with thyroid dysfunction and increases cardiovascular risk both per se and via high TC and LDL-C levels, the association of the latter with FT(3) and FT(4) levels has not yet been fully investigated in T2DM. While trying to fill this gap in 296 elderly outpatients with T2DM, we found that TC and LDL-C correlated negatively with FT(4) and positively with FT(3). When divided according to treatment by oral hypoglycaemic agents (OHA) and insulin (IT), they reacted differently with respect to investigated associations: in the OHA's TC and LDL-C correlated negatively with FT(4) and showed no association with FT(3), whereas, in the IT's TC and LDL-C correlated positively with FT(3) and negatively with FT(4). When controlled for possible confounding factors, these associations did not change in the IT's but were missing in the OHA's. Recent literature reports upon complex hypothalamic and peripheral interactions between T2DM and thyroid, and suggests T(3) to enhance cholesterol synthesis and to have a role in insulin resistance states. Further investigations are needed to understand the intimate mechanisms of lipid metabolism in T2DM with respect to thyroid function.

Sex hormones and adipokines in healthy pre-menopausal, post-menopausal and elderly women, and in age-matched men: data from the Brisighella Heart study

BACKGROUND

Sex hormones and adipokines seem to differently interact in both genders at different ages.

AIM

To comparatively evaluate the serum level of adipokines and sex hormones in healthy non-pharmacologically treated premenopausal women, post-menopausal women, and elderly women, and in age-matched men.

SUBJECTS

From the historical cohort of the Brisighella Heart Study we selected 199 adult healthy subjects (males: 89; females: 110), aged 62.5±12.4 yr. Men and women included in the age-class subgroups were matched for body mass index (BMI), waist circumference, blood pressure, heart rate, fasting plasma glucose, plasma lipids.

RESULTS

Leptin did not differ among various age classes in men, while pre-menopausal women displayed significantly lower serum leptin than post-menopausal women (-6.7 ± 2.2 pg/ml, p=0.036). Post-menopausal women had significantly greater serum leptin when compared with age-matched men (+13.1 ± 2.0 pg/ml, p<0.001); the same was observed for elderly women when compared with elderly men (+11.2 ± 2.3 pg/ml, p<0.001). At any age, women had significantly lower serum testosterone/estrone ratio than age-matched men (p<0.01). Serum DHEAS was inversely proportional to age in both genders. The main predictors of adiponectin level are age in men (p=0.027) and BMI in women (p=0.003). The main predictors of leptin level are BMI and the testosterone/estrone ratio in both sexes (p<0.05). The testosterone/estrone ratio is also the main predictor of ghrelin levels in women (p=0.006).

CONCLUSION

Sex hormones and adipokines show specific interactions in the two genders and in different age-classes in a representative sample of adult healthy subjects.

Frailty and muscle metabolism dysregulation in the elderly

The frailty syndrome is increasingly recognized by geriatricians to identify elders at an extreme risk of adverse health outcomes. The physiological changes that result in frailty are complex and up to now have been extremely difficult to characterize due to the frequent coexistence of acute and chronic illness. Frailty is characterized by an decline in the functional reserve with several alterations in diverse physiological systems, including lower energy metabolism, decreased skeletal muscle mass and quality, altered hormonal and inflammatory functions. This altered network leads to an extreme vulnerability for disease, functional dependency, hospitalization and death. One of the most important core components of the frailty syndrome is a decreased reserve in skeletal muscle functioning which is clinically characterized by a loss in muscle mass and strength (sarcopenia), in walking performance and in endurance associated with a perception of exhaustion and fatigue. There are a number of physiological changes that occur in senescent muscle tissues that have a critical effect on body metabolism. The causes of sarcopenia are multi-factorial and can include disuse, changing hormonal function, chronic diseases, inflammation, insulin resistance, and nutritional deficiencies. In this review, we will explore the dysregulation of some biological mechanisms that may contribute to the pathophysiology of the frailty syndrome through age-related changes in skeletal muscle mass and function.

Harmonized Italian version of the Aging Males' Symptoms scale

INTRODUCTION

The interest in clinical investigations in health-related quality of life (HRQoL) of aging men has increased over recent years, particularly in the context of partial androgen deficiency. The aim of this paper is to inform the scientific community about a harmonized Italian Aging Males' Symptoms (AMS) scale.

METHODS

There were two slightly different Italian AMS scales, which both underwent an up-to-date linguistic & cultural translation process, i.e., were both valid to be applied in clinical research. However, there are potential long-term problems associated with having two Italian language versions of the scale in the same country. Therefore, an ad hoc committee of key persons related to both versions met with the scale's developer, to create a harmonized single Italian AMS.

RESULTS

The harmonization meeting came up with a consensus item-by-item and the new Italian reference scale was agreed upon. It was decided that this scale should be published to avoid any confusion among future users.

CONCLUSION

The Italian AMS scale published in this paper should be used for future clinical and other research.

Morpho-functional alterations in testicular and nervous cells submitted to modelled microgravity

Humans, as well as other life forms, have developed on earth under the terrestrial gravitational field. Questions concerning the effect of the gravity vector changes on the animal physiology have begun to emerge only in the last decades. Physiological alterations were observed during space flights, but space-born investigations at cellular levels are still very limited. Earth-bound simulations of low gravity obtained with the 3-dimensional Random Positioning Machine are extensively utilized to explore the effects of microgravity on cell function. After only a few minutes, weightlessness affected the cytoskeleton of lymphocytes, astrocytes, neurons and testicular cells, disorganizing microtubules, intermediate filaments and microfilaments. Cell division was impaired, mitochondria were disrupted and apoptotic phenomena occurred. Expression of proteins involved in transmembrane ion and water transport were also affected. In the Leydig cells the key enzymes (3beta- and 17beta-hydroxysteroid dehydrogenases) leading to testosterone synthesis were depressed. However, after 20 h of clinorotation the cells were able to synthesize heat shock proteins that initiated protection and recovery. The cytoskeleton was again well organized, normal mitosis occurred and the percentage of apoptotic cells returned to the range of 5%, similar to the control cultures. Ion and water transmembrane proteins and steroid dehydrogenases returned to normal levels. Long-term experiments showed that low gravity induced only transient alterations in the cultured cells, which were able to adapt to the gravity vector changes and to regain normal activity. These data may explain the physiological adaptation occurring in astronauts during and after space flights.

The pituitary-testicular axis in microgravity: analogies with the aging male syndrome

Extraterrestrial exploration has gone on for decades before reversible testicular failure was shown to be a consequence of space flight in humans and animals at the end of the XXth century. This phenomenon was initially thought to depend on the psycho-physical stress expected to derive from a decidedly unusual environment, but the lack of consistent data concerning cortisol increase and/or gonadotrophin suppression pointed to the possibility of a primary defect. This was indirectly confirmed by the observation that a continuum of testicular androgen secretion potential exists from microgravity to centrifuge-derived hypergravity. Further experiments using tissue slices and suspended cells confirmed a direct inhibitory effect of microgravity upon testicular androgen production. A parallel deterioration of major physiological parameters, such as bone density, muscle mass/force, red blood cell mass, hydration and cardiopulmonary performance, has been repeatedly described during space missions, which, luckily enough, fully recover within days to weeks after landing, the time lag depending on single organ/system adaptation rates. According to the Authors of the present review, when taking together all reported changes occurring in space, a picture emerges closely resembling the so-called aging male syndrome, which is currently the object of daily screening and clinical care in their endocrine unit, so that microgravity may become a tool for better understanding subtle mechanisms of testicular senescence.

Neuroendocrine changes involved in the genesis of HD-induced orthostatic intolerance

The aim of the present study was to analyze the role played by norepinephrine and epinephrine in Symptomatic (S) vs Non-Symptomatic (NS) subjects within a group of healthy volunteers undergoing a 4-hour-head-down bed rest study at -6 degrees.

Microgravity-induced alterations in cultured testicular cells

Cultured STe cells (2n karyotype) from swine testis were submitted to simulated microgravity using a 3D Random Positioning Machine for 5 min., 15 min., 30 min., 1 h and 23 h. Sample processing included: histological characterization of cell types, immunohistochemical identification of (i) microtubules (a-tubulin), (ii) alkaline phosphates, (iii) 3 beta-hydroxy-steroid-dehydrogenase (3?-HSDH), and histochemical lipid analyses. After 5 min. simulated microgravity a slight microtubule disorganisation occurred, which increased dramatically with increasing microgravity duration. After 23 h microtubule arrays were completely disrupted. 3 beta-HSDH immunostaining was detectable only in one cell type: under control conditions and 5 min. into microgravity immunoreactivity was strong, but completely disappeared thereafter. Immunostaining intensity for alkaline phosphates, a good marker for myoid cells, decreased after 15 min. in microgravity.

Microgravity-induced apoptosis in cultured glial cells

Apoptosis is a form of naturally occurring cell death that plays fundamental roles during embryonic developement. In adults, it neatly disposes of cells damaged by injuries provoked by external causes such as UV radiation, ionisation and heat shock. Alteration of the gravity vector may be one of the external apoptosis inducers. Neurophysiological impairment signs were seen during space flights in astronauts, but very few studies were carried out on the nervous system and none at the cellular level. In this study, we submitted cultured C6 glioma cells to microgravity (0xg) of varying duration, obtained by clinorotation in a Fokker three-dimensional clinostat for 15 min, 30 min, 1h, 20h or 32h. After 30 min at 0xg, numerous nuclei underwent the classical morphological alterations (chromatin condensation, nuclear fragmentation, apoptotic bodies) that lead to the programmed cell death. After 30 min at 0xg, immunostaining for the enzyme caspase-7 was present in the cytoplasm of many cells concurrently with DNA fragmentation identified by the TUNEL method. At 32h, the number of apoptotic nuclei was much reduced indicating the ability of glial cells to adapt to altered gravity.

Microgravity-induced programmed cell death in astrocytes

Cultured astrocytes were submitted to simulated microgravity using a Fokker clinostat under continuous rotation (60 rpm) for 15', 30', 1h, 20h and 32h. Samples processing included (i) nuclear stainings using Propidium Iodide and 4,6-diamidino-2-phenilindole, dihydro chloride, (ii) immunohistochemical identification of Caspase-7, (iii) identification of DNA fragmentation using the terminal dUTP nick end labelling and (iv) Scanning Electron Microscope analysis. After 30' at simulated microgravity the glial cells showed morphological evidence of apoptosis: cell shrinkage, chromatin condensation, nuclear blebs and fragmentation. The enzyme caspase-7 was present and DNA fragmentation was evident. After 32h the density of the cell population was much lower than that observed in controls.

Hormonal regulation during a 60-day confinement (ESA-EXEMSI'92) in humans

EXEMSI'92 was a 60-day isolation and confinement experiment with an international crew. During this second experiment of the European Space Agency (the first one was a 28-day confinement with 6 men: ISEMSI'90), blood volume regulating hormones and water balance were studied. During ISEMSI'90, stress level was elevated as shown by specific markers and we observed some interesting results which have been already observed before, during bed-rest experiments. Thus, our conclusion was that some of the physiological effects observed during bed rest could be the consequence of the "confinement effect" and/or stress imposed to the subjects during such experiments. The aim of the present physiological study was: 1/to define the origin of the blood pressure increase seen during ISEMSI'90; 2/ to study the blood volume regulating hormones (ANP, renin, aldosterone) variations; 3/ to determine the dehydration level by measuring the total body water with the doubly labeled water (DLW) method and fluid balance in general.

Leptin levels in diabetic and nondiabetic subjects

The role of leptin in human pathophysiology elicits considerable interest in view of its potential role as a treatment tool for obesity and other insulin resistant states, like type 2 diabetes mellitus (T2DM). Leptin has been extensively studied in obese humans, and much less so in other pathologic conditions. Leptin level has been reported to correlate with percent body fat mass (%FM), fasting serum insulin (FPI), insulin sensitivity and blood pressure. The aim of this study was to compare the leptin concentration, and its relationship with some anthropometric and biochemical parameters related to insulin resistance in 140 moderately obese type 2 diabetics (T2DM) and 160 age and weight matched non-diabetic controls in order to get a better insight into the possible role of leptin in the metabolic abnormalities of diabetes. The leptin levels were lower in the diabetic population only when both sexes were combined (p < 0.05) and were higher in the females of both groups. Among the nondiabetics, the leptin levels appeared to be related to BMI, %FM, HDL and FPI, while this was not the case in the diabetics. After correction for BMI, leptin appeared to be correlated with the FPI levels only in the non-diabetic females. When plasma leptin was included in a multiple linear regression model with plasma leptin as a dependent variable, BMI, W:Hr and FPI levels were significantly related to leptin in the non diabetic population, while no relationship reached the level of statistical significance among the diabetics, with the exception of the borderline value for the FPI (p = .052). In conclusion, leptin levels were independent of any of the parameters examined in our diabetic population, possibly due to the progressive loss of the normal mechanisms of leptin regulation with advancing disease. Conclusive data can only be obtained from the longitudinal study of a cohort of newly diagnosed diabetic subjects.

Simulated microgravity induces alteration in the central nervous system

To investigate whether the signs of neurophysiological impairment observed in flight may be traced back to cytomorphology, we undertook a ground-based study focusing upon the architecture of cultured glial cells under simulated microgravity obtained by three-dimensional clinorotation.

Adaptation of the human endocrine system to microgravity in the context of integrative physiology and ageing

This review deals with changes occurring in space in different endocrine systems. Sections are dedicated to hormones involved in bone remodelling, the hypothalamic-pituitary-adrenal axis, the hypothalamic-pituitary-thyroid axis, pancreatic hormones, the hypothalamic-pituitary-gonadal axis and the hypothalamic-pituitary-somato-mammotropic system. In space, most systems - especially those regulating bone/muscle metabolism and reproduction - undergo changes resembling those observed during senescence, but recover within weeks or months after return. This suggests space as a possible experimental model for the study of "reversible ageing processes". Studying ageing through space technology might give us the opportunity to combine the holistic view of integrative physiology with the most ambitious goal of the present scientific community, i.e. to yield successful ageing by promoting chronic disease prevention studies and by optimizing safe, anti-ageing therapeutic protocols.

Testosterone urinary excretion rate increases during hypergravity in male monkeys

Real and simulated microgravity impairs T secretion both in animals and in the human. To verify whether hypergravity might enhance T secretion as a consequence of an opposite mechanical effect, 6 male monkeys were centrifuged at 2 G for 3 weeks after a 1 G stabilization period lasting 3 weeks and then taken back to 1 G for 1 week and urine were collected daily for T excretion measurement. Significantly higher level were observed during the initial 2 G phase as compared to pre- and post centrifugation periods and the trend was the same during the remaining 2 G period. This may reflect changes in testicular perfusion rather than endocrine adaptation per se.

Leptin and aging: correlation with endocrine changes in male and female healthy adult populations of different body weights

Aging is associated with changes in plasma levels of several hormones. There are conflicting reports on whether circulating leptin levels change during aging, the possible explanation for which is that alterations in adiposity and body mass index (BMI) also occur. In this study we measured plasma leptin and other hormonal parameters known to influence leptin in 150 men and 320 women of a wide age (18-77 yr) and BMI (18.5-61.1 kg/m2) range. Subjects of each gender were separated into 2 groups of similar BMI, i.e. nonobese (BMI, <30) and obese (BMI, >30), and treated separately. Statistical analysis was performed, treating each group of subjects as a whole population or divided into age groups (<30, 30-50, and >50 yr). BMI-adjusted leptin levels were progressively lower with increasing age in women, with a consistent fall after menopause (-21%; P < 0.001); in men, leptin levels also tended to be lower in subjects more than 50 yr of age, but the reduction was not significant. Multiple linear regression analysis, performed on subjects treated either as a whole population or divided into obese and nonobese, showed that in both genders BMI and age were independent contributors of leptin levels, and there was an inverse relationship between leptin and age in both obese (standardized coefficient beta = -0.25 in women and -0.23 in men; P < 0.01) and nonobese (-0.22 in women and -0.20 in men; P < 0.05) subjects. The correlation of leptin and age with plasma levels of sex and thyroid hormones, GH, insulin-like growth factor I, PRL, and insulin was also evaluated. The variables that correlated with leptin were included in a multiple regression model that included BMI and age. Testosterone in men (-0.43 in nonobese and -0.19 in obese; P < 0.05) and estradiol in women (0.22 in nonobese and 0.24 in obese; P < 0.05) were important contributors to leptin levels; also, dehydroepiandrosterone sulfate in obese women (-0.16) and sex hormone-binding globulin in obese subjects of both genders (0.15 in women and 0.19 in men) were significant determinants in the model. However, none of the hormonal parameters abolished the negative correlation between leptin and age or the gender difference in leptin levels. In conclusion, our data show that in adult humans of different body weight, serum leptin gradually declines during aging; leptin reduction is higher in women than in men, but it is independent from BMI and other age-related endocrine changes.

Hormonal changes in humans during spaceflight

Readers of this review may feel that there is much more that we do not know about space endocrinology than what we know. Several reasons for this state of affairs have been given: 1. the complexity of the field of endocrinology with its still increasing number of known hormones, releasing factors and precursors, and of the interactions between them through various feedback mechanisms 2. the difficulty in separating the microgravity effects from the effects of stress from launch, isolation and confinement during flight, reentry, and postflight re-adaptation 3. the experimental limitations during flight, such as limited number of subjects, limited number of samples, impossibility of collecting triple samples for pulsatile hormones like growth hormone 4. the disturbing effects of countermeasures used by astronauts 5. the inadequacy of postflight samples for conclusions about inflight values 6. limitations of conclusions from animal experiments and space simulation studies The endocrinology field is divided in to nine systems or axes, which are successively reviewed: 1. Rapid bone demineralization in the early phase of spaceflight that, when unopposed, leads to catastrophic effects after three months but that slows down later. The endocrine mechanism, apart from the effect of exercise as a countermeasure, is not yet understood. 2. The hypothalamic-pituitary-adrenal axis is involved in stress reactions, which complicate our understanding and makes postflight analysis dubious. 3. In the hypothalamic-pituitary-gonadal axis, pulsatility poses a problem for obtaining representative values (e.g., for luteinizing hormone). Reproduction of rats in space is possible, but much more needs to be known about this aspect, particularly in women, before the advent of space colonies, but also in males because some evidence for reversible testicular dysfunction in space has been found. 4. The hypothalamic-pituitary-somato-mammotrophic axis involves prolactin and growth hormone. The latter also acts as a stress hormone and its secretion is greatly decreased in spaceflown rats, but not in astronauts, which may be due to differences in the regulation of growth hormone secretion between rats and humans. 5. The hypothalamic-pituitary-thyroid axis involves the thyroid hormones thyroxine and triiodothyronine, which are lowered in space, suggesting mild hypothyroidism. 6. The renin-angiotensin-aldosterone axis, which regulates water and electrolytes, involves antidiuretic hormone and two natriuretic peptides and shows paradoxical behavior in space. 7. Erythrocyte mass regulation involves erythropoietin, and space anemia is still not explained. 8. The endocrine pancreas involves insulin and glucagon, with loss of insulin sensitivity in space due to lack of exercise, which phenomenon requires more study before the advent of space colonies. 9. The sympathetic system acts through epinephrine, norepinephrine and dopamine and seems to have an increased activity in space in contrast to what had been widely believed. From the foregoing conclusions, it is clear that much further study is needed in all fields of space endocrinology. On the other hand, future studies will allow us to understand what happens in a given endocrine subsystem in the absence of the "gravity factor", the perturbing factor to which the human race has become adapted through thousands of years of evolution. This should provide us with a fuller understanding of the internal homeostatic mechanisms. An important point is that some endocrine systems seem to undergo changes in space that resemble those observed during senescence, but after spaceflight, recovery always occurs within weeks or months after return. This is particularly true for the systems regulating bone and muscle metabolism and reproduction, exactly as happens with the immune, neurosensory, and cardiovascular systems. Further space research may help us find new insights in the pathophysiology of aging and hopefully define novel prev

Leptin and androgens in male obesity: evidence for leptin contribution to reduced androgen levels

Leptin circulates in plasma at concentrations that parallel the amount of fat reserves. In obese males, androgen levels decline in proportion to the degree of obesity. Recently, we have shown that in rodent Leydig cells leptin inhibits hCG-stimulated testosterone (T) production via a functional leptin receptor isoform; others have found that leptin inhibits basal and hCG-induced T secretion by testis from adult rats. In this study, we further investigated the relationship linking leptin and androgens in men. Basal and hCG-stimulated leptin and sex hormone levels were studied in a large group of men ranging from normal weight to very obese (body mass index, 21.8-55.7). Initial cross-sectional studies showed that circulating leptin and fat mass (FM) were inversely related with total and free T (r = -0.51 and r = -0.38, P < 0.01 and P < 0.05, respectively). Multiple regression analysis indicated that the correlation between leptin or FM and T was not lost after controlling for SHBG and/or LH and/or estradiol (E2) levels and that leptin was the best hormonal predictor of the lower androgen levels in obesity. Dynamic studies showed that in obese men the area under the curve of T and free T to LH/hCG stimulation (5000 IU i.m.) was 30-40% lower than in controls and inversely correlated with leptin levels (r = -0.45 and r = -0.40, P < 0.01 and P < 0.05, respectively). Also, LH/hCG-stimulation caused higher increases in 17-OH-progesterone to T ratio in obese men than in controls, whereas no differences were observed between groups either in stimulated E2 levels or in the E2/T ratio. In all subjects, the percentage increases from baseline in the 17-OH-progesterone to T ratio were directly correlated with leptin levels or FM (r = 0.40 and r = 0.45, P < 0.01), but not with E2 or other hormonal variables. In conclusion, our studies, together with previous in vitro findings, indicate that excess of circulating leptin may be an important contributor to the development of reduced androgens in male obesity.

The endocrinology of aging and its relationship to space physiology

During the last century the number of people over 65 years of age has increased more than four-fold in the industrialized countries and by the year 2030 might account for 20% of the population. Life expectancy at birth is now about 75 (vs. 47 in 1900) and at 75 is 86 years. The scientific community is thus getting more and more interested in understanding the behavioral and clinical features of centenarians. During aging many endocrine systems undergo anatomic and functional changes at different times and with variable intensities, depending on individual genotypes and phenotypes. The most common finding is impaired anabolism, rather than increased catabolism, so that the hypothesis has been put forward that aging itself stems from the functional deterioration of the endocrine system. From a practical point of view, two main questions arise: (i) to which extent the endocrine glands accelerate physical decay?; (ii) may hormonal replacement ensure health at least longer than nowadays?

Gender affects the pattern of neuroendocrine response to head-up tilt

One of the major concerns in space medicine is post-mission postural hypotension. Since the beginning, most of the studies have been aimed at the identification of mechanical and neuroautonomic mechanisms within the cardiovascular system potentially involved in this phenomenon. Some gender differences in the cardiovascular reactivity to changing posture have been described so far, which still need better clarification. Moreover, the neuroendocrine contribution to postflight readaptation deserves more indepth studies. Sudden passive head-up tilting is considered to be a good simulation method for hemodynamic changes occurring during transition from 0xg to 1xg. The aim of this study was to verify whether cardiovascular or neuroendocrine changes occurring after sudden passive +70 degrees head-up tilt (HUT) became already evident within 10 min and were similar in healthy young-adult men and women.

Indirect evidence of CNS adrenergic pathways activation during spaceflight

BACKGROUND

Microgravity causes cephalad fluid shift and compensatory mechanisms. Hormonal changes suggestive of peripheral sympathetic (catecholaminergic) nervous system activation have been recently found in astronauts during flight. Simulation studies showed increased perivascular sympathetic fiber density in the rat brain.

HYPOTHESIS

Intracranial microcirculatory adaptations might also occur in astronauts, involving an increase in the turnover rate of catecholamines, i.e., norepinephrine (NE) and its precursor, Dopamine (DA). DA is known to inhibit prolactin (PRL) release and to enhance growth hormone (GH) secretion by the pituitary. Therefore, increased brain dopaminergic activity would result into lower circulating PRL concentrations. At the same time, plasma levels of GH and of its effector insulin-like growth factor-1 (IGF-1) would increase during flight.

METHODS

Circulating cortisol (CS), PRL, GH and IGF-1 levels were measured 2 d preflight, inflight (4-5 d after launch) and on different days postflight in four astronauts involved in the Spacelab D-2 mission.

RESULTS

No significant changes were found in CS concentrations. PRL decreased while GH and IGF-1 increased inflight (p < 0.05). After flight no statistically relevant hormonal changes were found with respect to preflight.

CONCLUSION

The observed hormonal changes were consistent with the original hypothesis that spaceflight might activate CNS adrenergic pathways. They occurred in the absence of two typical markers of stress, namely CS and PRL increase, thus ruling out any non-specific effect of acute stress on the results. In agreement with the most recent results of real and simulated microgravity studies performed in both the experimental animal and in man, these data lend support to the hypothesis that the CNS adrenergic pathways are also activated in the human during spaceflight.

Outcome results of the Fosinopril Versus Amlodipine Cardiovascular Events Randomized Trial (FACET) in patients with hypertension and NIDDM

OBJECTIVE

ACE inhibitors and calcium antagonists may favorably affect serum lipids and glucose metabolism. The primary aim of the Fosinopril Versus Amlodipine Cardiovascular Events Randomized Trial (FACET) was to compare the effects of fosinopril and amlodipine on serum lipids and diabetes control in NIDDM patients with hypertension. Prospectively defined cardiovascular events were assessed as secondary outcomes.

RESEARCH DESIGN AND METHODS

Inclusion criteria included a diagnosis of NIDDM and hypertension (systolic blood pressure of > 140 mmHg or diastolic blood pressure of > 90 mmHg). Exclusion criteria included a history of coronary heart disease or stroke, serum creatinine > 1.5 mg/dl, albuminuria > 40 micrograms/min, and use of lipid-lowering drugs, aspirin, or antihypertensive agents other than beta-blockers or diuretics. A total of 380 hypertensive diabetics were randomly assigned to open-label fosinopril (20 mg/day) or amlodipine (10 mg/day) and followed for up to 3.5 years. If blood pressure was not controlled, the other study drug was added.

RESULTS

Both treatments were effective in lowering blood pressure. At the end of follow-up, between the two groups there was no significant difference in total serum cholesterol, HDL cholesterol, HbA1c, fasting serum glucose, or plasma insulin. The patients receiving fosinopril had a significantly lower risk of the combined outcome of acute myocardial infarction, stroke, or hospitalized angina than those receiving amlodipine (14/189 vs. 27/191; hazards ratio = 0.49, 95% CI = 0.26-0.95).

CONCLUSIONS

Fosinopril and amlodipine had similar effects on biochemical measures, but the patients randomized to fosinopril had a significantly lower risk of major vascular events, compared with the patients randomized to amlodipine.

The effect of microgravity on testicular androgen secretion

BACKGROUND

Spaceflight causes a number of physiological changes in the human body. Most would consider space travel to be a stressful event even for well-trained astronauts. Should this be true, pituitary gonadotrophins (mainly LH) and testicular androgens, like testosterone (T), should decrease inflight in male astronauts. We therefore hypothesized that lowered testicular androgen levels might occur in men during spaceflight, due to stress-dependent lowered LH concentrations.

METHODS

In order to test this hypothesis, on different day pre-, in- and postflight we assayed wake-time salivary and urinary T in four astronauts, as well as wake-time plasma levels of adrenocorticotropin (ACTH), cortisol (CS), LH, T and its peripherally active metabolite 3-alpha-diol glucuronide (3ADG). In order to compare clinical to subjective data, all 7 male crewmembers anonymously answered a daily questionnaire from pre- to postflight asking them to self-rate sexual drive and potency, muscle strength and mood.

RESULTS

Salivary, urinary and plasma T, as well as 3ADG, decreased during flight, while LH unexpectedly increased inflight (p < 0.05). A parallel decrease in sexual drive was observed (p < 0.05). A dramatic recovery of salivary T was found on R + 1.

CONCLUSIONS

This was the first time that spaceflight was demonstrated to cause temporary, still dramatic hypoandrogenism which was not due to blunted pituitary gonadotrophin secretion. The cause for hypoandrogenism is unknown but it may depend on fluid shift affecting testicular function or androgen distribution in various body compartments.

Changes in human adrenal and gonadal function onboard Spacelab

Astronauts have to face chronic stress during the mission period. This might cause: (i) increased adrenocortico-trophin (ACTH) and cortisol (Cort) secretion; (ii) impaired luteinizing hormone (LH) output with consequent testosterone (T) hyposecretion in men. Moreover, should the subjects prove not to synchronize their inner clocks to the time shift protocols defined by NASA, most results would be questionable. The aim of this study was to verify if plasma testicular androgens were lower than baseline and Cort biorhythm was preserved in male astronauts during a short duration flight.

Hormonal, water balance, and electrolyte changes during sixty-day confinement

The EXEMSI experiment has made it clear that it is difficult to perform psychological and physiological protocols satisfactorily in the same study. It is, therefore, essential that the objectives of study be defined clearly before the start. While behavioral and psychological studies may be possible and provide valid results for a small group of mixed gender, it is more difficult to conduct valid physiological studies due to large differences between individuals and even in the same individual over time. As stated before, it is unusual in space research on humans and even during space simulation studies to have large and homogeneous groups of subjects. The consequence is that the results remain tentative. For a better understanding of the physiological data collected during the ISEMSI ad EXEMSI experiments, they should be correlated with the results of the psychological studies. One of the conclusions drawn from the ISEMSI experiment was that confinement provides a valuable parallel to other simulations of weightlessness, such as bedrest. The same pattern of changes in parameters like the blood volume regulating hormones renin and aldosterone was observed as in bedrest. After the EXEMSI study we can say that the conditions imposed by confinement, high work load, and stress, potentiate these effects. This implies that in using head-down bedrest as a weightlessness simulation the confinement effects must be identified by setting adequate control conditions for the head-down position, for short-term as well as for long-term simulations. Indeed, we have seen in the two isolation studies that confinement may have its effects at the beginning of the isolation period (EXEMSI) as well as during the entire isolation period (ISEMSI). In planning for EXEMSI we wanted to obtain more insight in some of the phenomena observed during ISEMSI by the introduction of new techniques such as the doubly labeled water method for determination of total body water. However, in some cases the opposite effects of those encountered in ISEMSI were found. This was probably due to the many changes in the experimental scenario, like number of subjects, mixed gender, living space per subject, and workload. Thus, for future isolation studies the operational scenario should be better examined and preferably standardized. Nevertheless, in such studies as well as in long-term sojourns in a space station, the crew size will not be larger than that of the EXEMSI crew. Physiologists will, therefore, have to become familiar with the study of small groups of subjects and to try to overcome the problems of large individual differences and statistical analysis of data from small groups.

Renal and endocrine responses in humans to isotonic saline infusion during microgravity

It was the purpose of this study to investigate how the endocrine and renal mechanisms of fluid volume control in humans (n = 4) adapt to microgravity by applying an intravenous isotonic saline infusion. The acute ground-based supine (Sup) and seated (Seat) positions were chosen as references. During microgravity, renal sodium excretion (UNaV) was doubled during the second and third hours after infusion compared with during Seat (P < 0.05) but blunted during the first hour after infusion compared with during Sup, leading to a reduction in cumulative UNaV (59 +/- 15 vs. 108 +/- 12 mmol/5 h; P < 0.05). Plasma norepinephrine (NE) attained the highest value 3 h after infusion during microgravity (31 +/- 5 x 10(-2) ng/ml vs. 19 +/- 1 and 13 +/- 3 x 10(-2) ng/ml for Seat and Sup, respectively; P < 0.05). Inflight levels of plasma renin and aldosterone were very similar to levels during Seat. In conclusion, 1) the microgravity-adapted renal responses to infusion reflected a condition in between that of ground-based Seat and Sup, respectively, and 2) the plasma levels of NE, renin, and aldosterone were elevated inflight and not related to the changes in UNaV and urinary flow rate. These observations are in contrast to results of ground-based simulation experiments and might partly have been caused by a prior inflight reduction in extracellular fluid volume. The high levels of NE during microgravity warrant further investigation.