Cortical and trabecular bone microarchitecture and turnover in alcohol-induced chronic pancreatitis: a histomorphometric study

Burden of bone disease in chronic pancreatitis: A systematic review and meta-analysis

BACKGROUND

Bone disease is an under-recognized cause of morbidity in chronic pancreatitis (CP). Over the past decade, publications of original studies on bone disease in CP has warranted synthesis of the evidence to ascertain the true burden of the problem.

AIM

To quantify the prevalence of osteopenia, osteoporosis, and fragility fractures in CP patients and investigate the associated clinical features and outcomes.

METHODS

A systematic search identified studies investigating bone disease in CP patients from Cochrane Library, Embase, Google Scholar, Ovid Medline, PubMed, Scopus, and Web of Science, from inception until October 2022. The outcomes included prevalence of osteopenia, osteoporosis, and fragility fractures, which were meta-analyzed using a random-effects model and underwent metaregression to delineate association with baseline clinical features.

RESULTS

Twenty-one studies were included for systematic review and 18 studies were included for meta-analysis. The pooled prevalence of osteopenia and osteoporosis in CP patients was 41.2% (95%CI: 35.2%-47.3%) and 20.9% (95%CI: 14.9%-27.6%), respectively. The pooled prevalence of fragility fractures described among CP was 5.9% (95%CI: 3.9%-8.4%). Meta-regression revealed significant association of pancreatic enzyme replacement therapy (PERT) use with prevalence of osteoporosis [coefficient: 1.7 (95%CI: 0.6-2.8); P < 0.0001]. We observed no associations with mean age, sex distribution, body mass index, alcohol or smoking exposure, diabetes with prevalence of osteopenia, osteoporosis or fragility fractures. Paucity of data on systemic inflammation, CP severity, and bone mineralization parameters precluded a formal meta-analysis.

CONCLUSION

This meta-analysis confirms significant bone disease in patients with CP. Other than PERT use, we observed no patient or study-specific factor to be significantly associated with CP-related bone disease. Further studies are needed to identify confounders, at-risk population, and to understand the mechanisms of CP-related bone disease and the implications of treatment response.

Mechano-structural alteration in proximal femora of individuals with alcoholic liver disease: Implications for increased bone fragility

Although increased hip fracture risk is noted in patients with alcoholic liver disease (ALD), their femoral microstructural and mechanical properties were not investigated previously. The present study aimed to analyze the associations between subregional deteriorations in femoral mechano-structural properties and clinical imaging findings to explain increased femoral fracture risk among ALD patients. This study analyzed proximal femora of 33 male cadaveric donors, divided into ALD (n = 13, 57 ± 13 years) and age-matched control group (n = 20, 54 ± 13 years). After pathohistological verification of ALD stage, DXA and HSA measurements of the proximal femora were performed, followed by micro-CT and Vickers microindentation of the superolateral neck, inferomedial neck, and intertrochanteric region. Bone mineral density and cross sectional area of the femoral neck were deteriorated in ALD donors, compared with healthy controls (p < 0.05). Significant ALD-induced degradation of trabecular and cortical microstructure and Vickers microhardness reduction were noted in the analyzed femoral regions (p < 0.05). Still, the most prominent ALD-induced mechano-structural deterioration was noted in intertrochanteric region. Additionally, more severe bone alterations were observed in individuals with an irreversible stage of ALD, alcoholic liver cirrhosis (ALC), than in those with an initial ALD stage, fatty liver disease. Observed osteodensitometric and mechano-structural changes illuminate the basis for increased femoral fracture risk in ALD patients. Additionally, our data suggest bone strength reduction that may result in increased susceptibility to intertrochanteric femoral fracture in men with ALD. Thus, femoral fracture risk assessment should be advised for all ALD patients, especially in those with ALC.

The Impact of Sedentary Lifestyle, High-fat Diet, Tobacco Smoke, and Alcohol Intake on the Hematopoietic Stem Cell Niches

Hematopoietic stem and progenitor cells maintain hematopoiesis throughout life by generating all major blood cell lineages through the process of self-renewal and differentiation. In adult mammals, hematopoietic stem cells (HSCs) primarily reside in the bone marrow (BM) at special microenvironments called “niches.” Niches are thought to extrinsically orchestrate the HSC fate including their quiescence and proliferation. Insight into the HSC niches mainly comes from studies in mice using surface marker identification and imaging to visualize HSC localization and association with niche cells. The advantage of mouse models is the possibility to study the 3-dimensional BM architecture and cell interactions in an intact traceable system. However, this may not be directly translational to human BM. Sedentary lifestyle, unhealthy diet, excessive alcohol intake, and smoking are all known risk factors for various diseases including hematological disorders and cancer, but how do lifestyle factors impact hematopoiesis and the associated niches? Here, we review current knowledge about the HSC niches and how unhealthy lifestyle may affect it. In addition, we summarize epidemiological data concerning the influence of lifestyle factors on hematological disorders and malignancies.

The relationship between healthy lifestyles and bone health: A narrative review

BACKGROUND

Bone health, especially osteoporosis among ageing populations, has become an important topic for both clinical and basic researchers. The relationship between bone health and healthy lifestyles has been frequently discussed. The present study focuses on the relationship between bone health and healthy lifestyles among older adults, based on a global comparison.

METHODS

This narrative review was performed by collecting clinical trials, basic research and reviews on lifestyle and bone health in PubMed database.

RESULTS

Positive effects of physical activity and negative effects of malnutrition, alcohol abuse, and cigarette smoking on bone health were revealed. The relationship between bone health and drinking coffee and tea is still inconclusive. Moreover, the diversity of each region should be aware when considering healthy lifestyles to improve bone health.

CONCLUSION

Healthy lifestyles are highly related to bone health, and different lifestyles may have different influences on regions with a high risk of bone diseases. It is practical to acknowledge the diversity of economic, religious, environmental and geological conditions in each region when providing suitable and effective recommendations for healthy lifestyles that can improve overall bone health.

The micro-structural analysis of lumbar vertebrae in alcoholic liver cirrhosis

Although vertebral fracture is more common among alcoholic liver cirrhosis patients when compared to general population, current data on three-dimensional micro-architecture are scarce. Our study showed significant trabecular deterioration in lumbar vertebrae obtained from alcoholic liver cirrhosis donors, suggesting that they should be advised to undergo early-stage screening for osteoporosis.

PURPOSE

Recent studies showed an increased incidence of vertebral fractures in alcoholic liver cirrhosis (ALC) patients, while data about vertebral micro-structure are still limited. The aim of this study was to compare trabecular and cortical micro-architecture of lumbar vertebrae between ALC patients and healthy age- and sex-matched controls.

METHODS

Our study included lumbar vertebral samples of male cadaveric donors, divided into ALC (n = 20, age: 59 ± 6 years) and control group (n = 20, age: 59 ± 8 years). Following pathohistological verification of liver cirrhosis, trabecular and cortical bone micro-architecture was analyzed by micro-computed tomography (micro-CT).

RESULTS

Micro-CT evaluation of the trabecular bone in lumbar vertebrae showed a significant decrease in bone volume fraction, trabecular thickness, trabecular number, and connectivity (p < 0.01). In contrast to trabecular deterioration, prominent alteration in cortical parameters was not observed in lumbar vertebrae of ALC patients (p > 0.05).

CONCLUSIONS

Our data indicate that susceptibility to non-traumatic fractures in ALC patients could be explained by alterations in trabecular bone micro-architecture. Thus, we genuinely recommend osteological screening of the lumbar spine for all ALC patients in order to evaluate individual fracture risk. Graphical abstract.

The Antagonist of Retinoic Acid Receptor α, ER-50891 Antagonizes the Inhibitive Effect of All-Trans Retinoic Acid and Rescues Bone Morphogenetic Protein 2-Induced Osteoblastogenic Differentiation

Background

Hypervitaminosis A, alcoholism or medical treatment for acute promyelocytic leukaemia may cause unphysiologically high accumulation of all-trans retinoic acid (ATRA), which could inhibit osteoblastogenesis, thereby triggering osteoporosis. We have shown that bone morphogenetic protein-2 (BMP-2) can only partially antagonize the inhibitive effects of ATRA. In this study, we hypothesized that antagonists of retinoic acid receptors (RARs) could further antagonize the inhibitive effect of ATRA and rescue BMP2-induced osteoblastogenesis.

Materials and Methods

We first screened the dose-dependent effects of the specific antagonists of RAR α, β and γ and transforming growth factor-beta receptor (ER-50891, LE-135, MM11253, and SB-43142, respectively) on ATRA-induced inhibition of the total cell metabolic activity and proliferation of preosteoblasts. We selected ER-50891 and tested its effects on osteoblastogenesis with the presence or absence of 1 μM ATRA and/or 200 ng/mL BMP-2. We measured the following parameters: Alkaline phosphatase activity (ALP), osteocalcin (OCN) expression and extracellular matrix mineralization as well as the level of phosphorylated Smad1/5.

Results

ER-50891 but not LE-135, MM11253, or SB-431542 significantly antagonized the inhibition of ATRA and enhanced the total cell metabolic activity and proliferation of preosteoblasts. Dose-dependent assays show ER-50891 could also rescue ATRA inhibited OCN expression and mineralization with or without the induction of BMP. ER-50891 also suppressed the ALP activity that was synergistically enhanced by BMP and ATRA. Neither ATRA, nor ER-50891 or their combination significantly affected the level of BMP-induced phosphorylated Smad1/5.

Conclusion

The antagonist of RARα, ER-50891 could significantly attenuate ATRA’s inhibitive effects on BMP 2-induced osteoblastogenesis.

Compromised bone strength in patients with alcoholic liver cirrhosis

Osteoporosis and/or osteopenia are frequently observed complications in alcoholic liver disease patients, especially in its irreversible stage (alcoholic liver cirrhosis - ALC). Current literature review regarding osteoporosis incidence increased fracture risk, bone mineral density changes, micro-structural alteration and pathogenetic mechanisms leading to ALC - induced decrease in bone quality is presented. It has been reported that osteoporosis is influenceing significant number of ALC patients, with particular accent on lumbar spine, as most commonly affected skeletal site. Several risk factors and ethio-pathogenic mechanisms have been associated with the loss of bone mineral density, in patients with ALC and other cirrhosis. Certain authors claim that dominant mechanism in ALC-induced bone loss is decrease in bone formation and osteoblastic function, while other results suggest increased bone remodeling as underlying cause of increased bone fragility in ALC patients. Increased bone fragility and susceptibility to osteoporotic fractures significantly affect life expectancy and quality of life in patients with ALC. Thus, osteological screening and individual fracture risk assessment are highly recommended for all patients with alcoholic liver cirrhosis.

Changes in the microstructure of compact and trabecular bone tissues of mice subchronically exposed to alcohol

BACKGROUND

Alcohol is one of the most commonly consumed neurotoxins by humans. Its negative effect on bone health is known for a long time. However, its impact on qualitative and quantitative 2D characteristics of the compact bone is still unclear. Therefore, the aim of this study was to investigate in detail the effects of subchronic alcohol exposure on compact and trabecular bone tissues microstructure of laboratory mice using 2D and 3D imaging methods. Ten clinically healthy 12 weeks-old mice (males) were randomly divided into two groups. Animals from experimental group (group E; n = 5) drank a solution composed of 15% ethanol and water (1.7 g 100% ethanol kg-1 b.w. per day) for 8 weeks, while those from control group (group C; n = 5) drank only water.

RESULTS

Subchronic exposure to alcohol leads to several changes in qualitative 2D characteristics of the compact bone such as the presence of primary vascular radial bone tissue in pars anterior of endosteal border and a higher number of resorption lacunae (five times more) in the middle part of substantia compacta. Morphometrical 2D evaluations of the compact bone showed significantly increased sizes of primary osteons' vascular canals (p < 0.05) in mice from the experimental group (E group). Sizes of Haversian canals and secondary osteons were not affected by alcohol consumption. In mice from the E group, significantly lower values for relative bone volume and bone mineral density of the compact bone were observed. In the trabecular bone, decreased values for bone volume, trabecular number, trabecular thickness and bone surface (p < 0.05) were documented.

CONCLUSIONS

Alcohol decreased not only bone volume and density of the compact bone, but it also reduced trabecular bone volume and leads to trabecular thinning. It caused vasodilation of primary osteons' vascular canals and increased porosity in the compact bone.

All-trans retinoic acid can antagonize osteoblastogenesis induced by different BMPs irrespective of their dimerization types and dose-efficiencies

Introduction

Alcoholism can lead to low mineral density, compromised regenerative bone capacity and delayed osteointegration of dental implants. This may be partially attributed to the inhibitive effect of all-trans retinoic acid (ATRA), a metabolite of alcohol, on osteoblastogenesis. Our previous studies demonstrated that heterodimeric bone morphogenetic protein 2/7 (BMP2/7) was a more potent BMP than homodimeric BMP2 or BMP7, and could antagonize the inhibitive effect of ATRA to rescue osteoblastogenesis.

Materials and methods

In this study, we compared the effectiveness of BMP2/7, BMP2 and BMP7 in restoring osteoblastogenesis of murine preosteoblasts upon inhibition with 1 µM ATRA, and we further analyzed the potential mechanisms. We measured the following parameters: cell viability, ALP, OCN, mineralization, the expression of osteogenic differentiation marker genes (Collagen I, ALP and OCN) and the expression of BMP signaling key genes (Dlx5, Runx2, Osterix and Smad1).

Results

BMP2/7 treatment alone induced significantly higher osteoblastogenesis compared to BMP2 and BMP7. When cells were treated by ATRA, BMP2/7 was superior only in rescuing cell viability and ALP activity, compared to BMP2 or BMP7. However, BMP2/7 was not superior to BMP2 or BMP7 in restoring OCN expression and extracellular mineralized nodules, or in rescuing expression of two key osteogenic genes, Dlx5 and Runx2. Irrespective of their dimeric types or potency, the selected BMPs could antagonize the inhibitory effect of ATRA on osteoblastogenesis.

Conclusion

The presence of ATRA, BMP2/7 still induced significantly higher cell viability and early differentiation than the homodimers. However, ATRA significantly attenuated the advantages of BMP2/7 in inducing late and final osteoblastogenic differentiation over the homodimers.

Chronic alcohol abuse in men alters bone mechanical properties by affecting both tissue mechanical properties and microarchitectural parameters

OBJECTIVE OF THE STUDY

Alcohol-induced secondary osteoporosis in men has been characterized by higher fracture prevalence and a modification of bone microarchitecture. Chronic alcohol consumption impairs bone cell activity and results in an increased fragility. A few studies highlighted effects of heavy alcohol consumption on some microarchitectural parameters of trabecular bone. But to date and to our knowledge, micro- and macro-mechanical properties of bone of alcoholic subjects have not been investigated.

PATIENTS

In the present study, mechanical properties and microarchitecture of trabecular bone samples from the iliac crest of alcoholic male patients (n=15) were analyzed and compared to a control group (n=8).

MATERIALS AND METHODS

Nanoindentation tests were performed to determine the tissue's micromechanical properties, micro-computed tomography was used to measure microarchitectural parameters, and numerical simulations provided the apparent mechanical properties of the samples.

RESULTS

Compared to controls, bone tissue from alcoholic patients exhibited an increase of micromechanical properties at tissue scale, a significant decrease of apparent mechanical properties at sample scale, and significant changes in several microarchitectural parameters. In particular, a crucial role of structure model index (SMI) on mechanical properties was identified.

CONCLUSIONS

3D microarchitectural parameters are at least as important as bone volume fraction to predict bone fracture risk in the case of alcoholic patients.

Alcohol: A Simple Nutrient with Complex Actions on Bone in the Adult Skeleton

BACKGROUND

Alcohol is an important nonessential component of diet, but the overall impact of drinking on bone health, especially at moderate levels, is not well understood. Bone health is important because fractures greatly reduce quality of life and are a major cause of morbidity and mortality in the elderly. Regular alcohol consumption is most common following skeletal maturity, emphasizing the importance of understanding the skeletal consequences of drinking in adults.

METHODS

This review focuses on describing the complex effects of alcohol on the adult skeleton. Studies assessing the effects of alcohol on bone in adult humans as well as skeletally mature animal models published since the year 2000 are emphasized.

RESULTS

Light to moderate alcohol consumption is generally reported to be beneficial, resulting in higher bone mineral density (BMD) and reduced age-related bone loss, whereas heavy alcohol consumption is generally associated with decreased BMD, impaired bone quality, and increased fracture risk. Bone remodeling is the principal mechanism for maintaining a healthy skeleton in adults and dysfunction in bone remodeling can lead to bone loss and/or decreased bone quality. Light to moderate alcohol may exert beneficial effects in older individuals by slowing the rate of bone remodeling, but the impact of light to moderate alcohol on bone remodeling in younger individuals is less certain. The specific effects of alcohol on bone remodeling in heavy drinkers are even less certain because the effects are often obscured by unhealthy lifestyle choices, alcohol-associated disease, and altered endocrine signaling.

CONCLUSIONS

Although there have been advances in understanding the complex actions of alcohol on bone, much remains to be determined. Limited evidence implicates age, skeletal site evaluated, duration, and pattern of drinking as important variables. Few studies systematically evaluating the impact of these factors have been conducted and should be made a priority for future research. In addition, studies performed in skeletally mature animals have potential to reveal mechanistic insights into the precise actions of alcohol and associated comorbidity factors on bone remodeling.

[Nutritional status in patients with chronic pancreatitis]

Chronic pancreatitis (CP) is an inflammatory disease of the pancreas, accompanied by damage to the functioning parenchyma and ducts to develop irreversible structural changes (fibrosis, calcification) and irreparable loss of the endocrine and exocrine functions of this organ. Maldigestion is a typical outcome of CP of any etiology with a long-term history. Fat malabsorption is considered as a basis for malnutrition in patients with CP. The severity of malnutrition in patients with CP correlates with three major pathogenetic factors: primary nutrient deficiency, pancreatic maldigestion and secondary malabsorption syndrome (nutrient loss), hypermetabolism that is caused by an inflammatory process in the pancreas and that determines the severity of the disease. Malnutrition in patients with CP is not just a complication of this disease, but has an important impact on its course. Patients with severe malnutrition are noted to have the significantly lower activity of pancreatic enzymes in the duodenal contents, feces, and blood, which is correlated with the smaller blood amount of total protein and albumin.

Twelve months of voluntary heavy alcohol consumption in male rhesus macaques suppresses intracortical bone remodeling

Chronic heavy alcohol consumption is a risk factor for cortical bone fractures in males. The increase in fracture risk may be due, in part, to reduced bone quality. Intracortical (osteonal) bone remodeling is the principle mechanism for maintaining cortical bone quality. However, it is not clear how alcohol abuse impacts intracortical bone remodeling. This study investigated the effects of long-duration heavy alcohol consumption on intracortical bone remodeling in a non-human primate model. Following a 4-month induction period, male rhesus macaques (Macaca mulatta, n=21) were allowed to voluntarily self-administer water or alcohol (4% ethanol w/v) for 22h/d, 7 d/wk for 12months. Control monkeys (n=13) received water and an isocaloric maltose-dextrin solution. Tetracycline hydrochloride was administered orally 17 and 3days prior to sacrifice for determination of active mineralization sites. Animals in the alcohol group consumed 2.7±0.2g alcohol/kg/d (mean±SE) during the 12months of self-administration, resulting in a mean daily blood alcohol concentration of 77±9mg/dl from samples taken at 7h after the start of a daily session. However, blood alcohol concentration varied widely from day to day, with peak levels exceeding 250mg/dl, modeling a binge-drinking pattern of alcohol consumption. The skeletal response to alcohol was determined by densitometry, microcomputed tomography and histomorphometry. Significant differences in tibial bone mineral content, bone mineral density, and cortical bone architecture (cross-sectional volume, cortical volume, marrow volume, cortical thickness, and polar moment of inertia) in the tibial diaphysis were not detected with treatment. However, cortical porosity was lower (1.8±0.5 % versus 0.6±0.1 %, p=0.021) and labeled osteon density was lower (0.41±0.2/mm(2)versus 0.04±0.01/mm(2), p<0.003) in alcohol-consuming monkeys compared to controls, indicating a reduced rate of intracortical bone remodeling. In concordance, plasma CTx was lower (2.5±0.3ng/ml versus 1.7±0.1ng/ml, p=0.028) in the alcohol group. These results suggest that chronic heavy alcohol consumption may negatively impact bone health, in part, by suppressing intracortical bone remodeling.

High prevalence of osteoporosis in patients with chronic pancreatitis: a systematic review and meta-analysis

BACKGROUND & AIMS

Patients with chronic pancreatitis may be at high risk for osteoporosis and osteopenia. We performed a systematic review and meta-analysis to determine the prevalence of osteoporosis and osteopenia in patients with chronic pancreatitis.

METHODS

Articles were identified from MEDLINE, EMBASE, and SCOPUS databases (through October 2012) and a manual search of the literature. The primary outcome measure was bone density, measured by dual-energy X-ray absorptiometry (T-score or Z-score). When available, data on the prevalence of osteopenia, bone mineral density, and bone mineral content also were recorded.

RESULTS

Ten studies including 513 patients were eligible for inclusion. Based on a random-effects model, the pooled prevalence rate for osteoporosis among patients with chronic pancreatitis was 23.4% (95% confidence interval, 16.6-32.0). The pooled prevalence for osteopenia was 39.8% (95% confidence interval, 29.1-51.6). The pooled prevalence rate for either osteoporosis or osteopenia was 65% (95% confidence interval, 54.7-74.0).

CONCLUSIONS

Based on meta-analysis, almost 1 of 4 patients with chronic pancreatitis have osteoporosis, and almost two-thirds of patients have either osteoporosis or osteopenia. Osteoporosis and osteopenia are underappreciated sources of morbidity in patients with chronic pancreatitis. Bone health management guidelines are urgently required in patients with chronic pancreatitis.

Diagnosis and treatment of pancreatic exocrine insufficiency

Pancreatic exocrine insufficiency is an important cause of maldigestion and a major complication in chronic pancreatitis. Normal digestion requires adequate stimulation of pancreatic secretion, sufficient production of digestive enzymes by pancreatic acinar cells, a pancreatic duct system without significant outflow obstruction and adequate mixing of the pancreatic juice with ingested food. Failure in any of these steps may result in pancreatic exocrine insufficiency, which leads to steatorrhea, weight loss and malnutrition-related complications, such as osteoporosis. Methods evaluating digestion, such as fecal fat quantification and the ¹³C-mixed triglycerides test, are the most accurate tests for pancreatic exocrine insufficiency, but the probability of the diagnosis can also be estimated based on symptoms, signs of malnutrition in blood tests, fecal elastase 1 levels and signs of morphologically severe chronic pancreatitis on imaging. Treatment for pancreatic exocrine insufficiency includes support to stop smoking and alcohol consumption, dietary consultation, enzyme replacement therapy and a structured follow-up of nutritional status and the effect of treatment. Pancreatic enzyme replacement therapy is administered in the form of enteric-coated minimicrospheres during meals. The dose should be in proportion to the fat content of the meal, usually 40-50000 lipase units per main meal, and half the dose is required for a snack. In cases that do not respond to initial treatment, the doses can be doubled, and proton inhibitors can be added to the treatment. This review focuses on current concepts of the diagnosis and treatment of pancreatic exocrine insufficiency.

Effect of the alcohol consumption on osteocyte cell processes: a molecular imaging study

We have previously shown microarchitectural tissue changes with cellular modifications in osteocytes following high chronic alcohol dose. The aim of this study was to assess the dose effect of alcohol consumption on the cytoskeleton activity, the cellular lipid content and modulation of differentiation and apoptosis in osteocyte. Male Wistar rats were divided into three groups: Control (C), Alcohol 25% v/v (A25) or Alcohol 35% v/v (A35) for 17 weeks. Bone mineral density (BMD) was assessed by DXA, osteocyte empty lacunae, lacunae surface, bone marrow fat with bright field microscopy. Osteocyte lipid content was analysed with transmission electron microscopy (TEM) and epifluorescence microscopy. Osteocyte apoptosis was analysed with immunolabelling and TEM. Osteocyte differentiation and cytoskeleton activity were analysed with immunolabelling and real time quantitative PCR. At the end of the protocol, BMD was lower in A25 and A35 compared with C, while the bone marrow lipid content was increased in these groups. More empty osteocyte lacunae and osteocyte containing lipid droplets in A35 were found compared with C and A25. Cleaved caspase-3 staining and chromatin condensation were increased in A25 and A35 versus C. Cleaved caspase-3 was increased in A35 versus A25. CD44 and phosphopaxillin stainings were higher in A35 compared with C and A25. Paxillin mRNA expression was higher in A35 versus A25 and C and sclerostin mRNA expression was higher in A35 versus C. We only observed a dose effect of alcohol consumption on cleaved caspase-3 osteocyte immunostaining levels and on the number of lipid droplets in the bone marrow.

Vitamin D and calcium status in South African adolescents with alcohol use disorders

Adequate vitamin D and calcium are essential for optimal adolescent skeletal development. Adolescent vitamin D insufficiency/deficiency and poor calcium intake have been reported worldwide. Heavy alcohol use impacts negatively on skeletal health, which is concerning since heavy adolescent drinking is a rising public health problem. This study aimed to examine biochemical vitamin D status and dietary intakes of calcium and vitamin D in 12-16 year-old adolescents with alcohol use disorders (AUD), but without co-morbid substance use disorders, compared to adolescents without AUD. Substance use, serum 25-hydroxyvitamin D (s-25(OH)D) concentrations, energy, calcium and vitamin D intakes were assessed in heavy drinkers (meeting DSM-IV criteria for AUD) (n = 81) and in light/non-drinkers without AUD (non-AUD) (n = 81), matched for age, gender, language, socio-economic status and education. Lifetime alcohol dose was orders of magnitude higher in AUD adolescents compared to non-AUD adolescents. AUD adolescents had a binge drinking pattern and "weekends-only" style of alcohol consumption. Significantly lower (p = 0.038) s-25(OH)D (adjusted for gender, smoking, vitamin D intake) were evident in AUD adolescents compared to non-AUD adolescents. High levels of vitamin D insufficiency/deficiency (s-25(OH)D < 29.9 ng/mL) were prevalent in both groups, but was significantly higher (p = 0.013) in the AUD group (90%) compared to the non-AUD group (70%). All participants were at risk of inadequate calcium and vitamin D intakes (Estimated Average Requirement cut-point method). Both groups were at risk of inadequate calcium intake and had poor biochemical vitamin D status, with binge drinking potentially increasing the risk of the latter. This may have negative implications for peak bone mass accrual and future osteoporosis risk, particularly with protracted binge drinking.

Chronic and intermittent exposure to alcohol vapors: a new model of alcohol-induced osteopenia in the rat

BACKGROUND

Different models are used to study the effects of chronic alcohol consumption on bone tissue in the rat. However, the current models take several months to show indices of osteopenia as observed in chronic drinkers. Numerous studies have supported that chronic and intermittent exposure to ethanol vapors has predictive validity as a model of alcohol dependence in humans. However, this model has never been applied to bone research to study its effects on the parameters that define osteopenia. This was the goal of this study in the rat.

METHODS

Male Wistar rats were exposed to ethanol vapor inhalation (n = 6) or air (controls, n = 6). Animals were exposed to chronic (11 weeks) and intermittent (14 hours a day) ethanol vapor reaching stable blood alcohol levels (BALs; 150 to 250 mg/dl) at the end of the third week of inhalation. After the sacrifice, right and left femur and tibia were dissected free of fat and connective tissue and bone mineral density (BMD) was assessed by dual X-ray absorptiometry. The microarchitecture of the femur was studied using microcomputed tomography.

RESULTS

The BMD of the left and right femurs and the left tibia was lower in the ethanol group compared with the control group. The bone volume fraction (BV/TV) and the bone surface density (BS/TV) were lower in the ethanol group compared with control animals. The trabecular number (Tb.N) was lower in the ethanol group while the trabecular spacing was higher.

CONCLUSIONS

The decrease in the BMD, BV/TV, and Tb.N is in the same range as what is observed in human drinkers and what is reported with other animal alcohol models (Lieber-DeCarli liquid diet, ethanol in the tap water). Therefore, this model could be useful to study the effects of chronic alcohol consumption in the bone research field and has the advantage of controlling easily targeted BALs.

Serum nutritional markers for prediction of pancreatic exocrine insufficiency in chronic pancreatitis

BACKGROUND

Methods for evaluation of pancreatic exocrine insufficiency (PEI) are expensive, labor intensive, and not available at many institutions. The aim of this study was to investigate if PEI in chronic pancreatitis (CP) can by predicted by nutritional markers in blood.

METHODS

A retrospective analysis of a prospectively collected database of CP patients was performed. Diagnosis of CP was based on endoscopic ultrasonography or magnetic resonance imaging. PEI was investigated by the (13)C-mixed triglyceride breath test. Hemoglobin, mean corpuscular volume, lymphocytes, prothrombin time, and serum levels of total protein, albumin, prealbumin, retinol binding protein, cholesterol, triglycerides, amylase, folic acid, vitamin B12, HbA1C, transferrin, ferritin, magnesium and zinc were analyzed.

RESULTS

114 patients were included in the study (97 males, mean age 48.1 years, 54 with alcohol etiology), 38 (33%) suffered from PEI. Magnesium below 2.05 mg/dL, hemoglobin, albumin, prealbumin and retinol binding protein below lower limit of normal and HbA1C above upper limit of normal were associated with PEI in univariate analysis. Magnesium below 2.05 mg/dL detected PEI with a sensitivity, specificity and positive and negative predictive values of 0.88 (95% confidence interval, 0.66-0.97), 0.66 (0.48-0.80), 0.58 (0.39-0.75) and 0.91 (0.73-0.98), respectively. The corresponding values were 1.00 (0.80-1.00), 0.55 (0.38-0.71), 0.52 (0.34-0.69) and 1.00 (0.82-1.00)) if one or more pathological tests among parameters significantly associated with PEI in was used as a positive test for PEI.

CONCLUSION

Serum nutritional markers can be used to predict the probability of PEI in CP and provide guidance in decisions on enzyme replacement therapy.

Alcohol and bone: review of dose effects and mechanisms

Alcohol is widely consumed across the world. It is consumed in both social and cultural settings. Until recently, two types of alcohol consumption were recognized: heavy chronic alcohol consumption or light consumption. Today, there is a new pattern of consumption among teenagers and young adults namely: binge drinking. Heavy alcohol consumption is detrimental to many organs and tissues, including bones, and is known to induce secondary osteoporosis. Some studies, however, have reported benefits from light alcohol consumption on bone parameters. To date, little is known regarding the effects of binge drinking on bone health. Here, we review the effects of three different means of alcohol consumption: light, heavy, and binge drinking. We also review the detailed literature on the different mechanisms by which alcohol intake may decrease bone mass and strength. The effects of alcohol on bone are thought to be both direct and indirect. The decrease in bone mass and strength following alcohol consumption is mainly due to a bone remodeling imbalance, with a predominant decrease in bone formation. Recent studies, however, have reported new mechanisms by which alcohol may act on bone remodeling, including osteocyte apoptosis, oxidative stress, and Wnt signalling pathway modulation. The roles of reduced total fat mass, increased lipid content in bone marrow, and a hypoleptinemia are also discussed.

High prevalence of low bone mineral density in patients with tropical calcific pancreatitis

OBJECTIVES

Patients with tropical calcific pancreatitis (TCP) have multiple risk factors for developing low bone mineral density (BMD). We studied BMD and serum 25-hydroxyvitamin D (25[OH]D) in north Indian TCP patients.

METHODS

In a cross-sectional study, 72 TCP patients (mean age, 31 ± 10 years) and 100 controls were studied. Serum 25(OH)D was measured in all subjects; BMD was measured by dual-energy x-ray absorptiometry in 56 adult patients and 4 children and compared with a reference Indian population.

RESULTS

Mean BMD and BMD Z-scores at the lumbar spine and total hip were significantly lower in all age groups. The BMD Z-scores at the lumbar spine and total hip were -1.0 ± 1.0 and -1.2 ± 1.2, respectively. Low bone density (Z-score ≤ -2 at ≥ 1 sites) was present in 22 (39%) adult patients and 3 of the 4 children studied. On multivariate analysis, BMD Z-scores were positively associated with body mass index and inversely with pancreatitis. Vitamin D deficiency (25[OH]D < 50 nmol/L) was equally prevalent in patients (86%) and controls (85%).

CONCLUSIONS

Despite their young age, patients with TCP have significantly low BMD. Measures to improve nutrition should be instituted in all TCP patients from an early age.