Is vitamin K deficiency a risk factor for osteoporosis in Crohn's disease?

Serum N-terminal telopeptide of type I collagen as a biomarker for predicting bone density loss in patients with Crohn disease

Background

The serum N-terminal telopeptide of type I collagen (NTx) is significantly higher in patients with Crohn disease (CD) than in healthy individuals and patients with ulcerative colitis. This study aimed to investigate whether an elevated serum NTx level is a risk predictor of osteoporosis in patients with CD.

Methods

Based on whether the femoral Z-score decreased over a 2-year period, 41 CD patients were divided into the ΔZ-score <0 group (Z-score decreased) and the ΔZ-score ≥0 group (Z-score did not decrease). The risk predictors of a femoral Z-score decrease were examined. Furthermore, we investigated the correlations between the ΔZ-score (which represents the change in the Z-score over a 2-year period) and the mean levels of biomarkers, including the Crohn Disease Activity Index (CDAI), serum albumin, C-reactive protein, and bone metabolism markers (including NTx) measured initially (i.e., in our previous study) and 2 years later (present study). The relationships between anti-tumor necrosis factor α (anti-TNF-α) therapy and serum NTx levels were also examined.

Results

Although there was no correlation between the mean CDAI and the ΔZ-score, the mean serum NTx and albumin levels were significantly correlated with the ΔZ-score (P<0.01 and P = 0.02, respectively). Furthermore, the femoral Z-score tended to be lower in the anti-TNF-α administration group than in the non-administration group.

Conclusions

These observations indicated that an elevated serum NTx could be a useful marker for predicting a decrease in the femoral bone mineral density in CD patients. Anti-TNF-α therapy maintained an elevated serum NTx level, suggesting that treatment with anti-TNF-α may help control increased bone resorption in CD patients.

Vitamin K deficiency leads to exacerbation of murine dextran sulfate sodium-induced colitis

BACKGROUND

Patients with inflammatory bowel disease (IBD) often exhibit vitamin K deficiency. Vitamin K has been shown to inhibit inflammation via interleukin (IL)-6 suppression. This study aimed to evaluate the effect of vitamin K in a murine model of colitis.

METHODS

Colitis was induced using dextran sulfate sodium (DSS) in mice fed either a vitamin K-deficient (K-def) or a vitamin K-supplemented (K-sup) diet. The clinical and histological severity of colitis was assessed, and levels of cytokine production from the spleen and colonic lamina propria were measured by enzyme-linked immunosorbent assay and quantitative real-time reverse transcription polymerase chain reaction. Cytokine expression levels in CD4(+), CD11b(+), and CD19(+) cells in the presence and absence of vitamin K [menatetrenone (MK-4)] were measured in vitro and apoptosis was determined by caspase 3/7 activity and Annexin V staining.

RESULTS

DSS administration resulted in significantly more severe body weight loss, shorter colon length, and higher histological scores in mice fed a K-def diet than those fed a K-sup diet. IL-6 expression in lamina propria mononuclear cells was significantly higher in the K-def group than in the K-sup group. IL-6 expression was significantly decreased in the presence of MK-4 in CD19(+) cells, but not in the CD4(+) and CD11b(+) subpopulations. Apoptotic cell population in CD19(+) cells was increased in the presence of MK-4 in vitro and in vivo.

CONCLUSIONS

Vitamin K exerts a protective effect against DSS colitis; this effect is associated with IL-6 downregulation. Vitamin K could be a potential treatment target for IBD.

An Increased Serum N-Terminal Telopeptide of Type I Collagen, a Biochemical Marker of Increased Bone Resorption, Is Associated with Infliximab Therapy in Patients with Crohn's Disease

BACKGROUND

Osteopenia and osteoporosis are considered to be extra-intestinal manifestations of inflammatory bowel disease (IBD). Anti-tumor necrosis factor (TNF)-α biologics have been introduced as novel medications for an active IBD. However, it is still not well documented whether anti-TNF-α affects the frequency of bone loss or abnormality of bone mineral markers among patients with IBD.

AIMS

This study was to investigate the biochemical basis of low bone mineral density (BMD) and increased turnover in IBD during infliximab (IFX) therapy.

METHODS

Forty patients with Crohn's disease (CD), 80 patients with ulcerative colitis (UC), and 65 age- and gender-matched controls were included. BMD was measured with dual-energy X-ray absorptiometry, and vitamins K and D were measured as serum undercarboxylated osteocalcin (ucOC) and 1,25-(OH)2D, respectively. Bone formation and resorption were based on measuring bone-specific alkaline phosphatase (BAP) and serum N-terminal telopeptide of type I collagen (NTx), respectively.

RESULTS

Significantly lower BMD was found in patients with UC and CD as compared to controls (P < 0.05). BAP, 1,25-(OH)2D, ucOC, and NTx were significantly higher in CD patients, but not in UC patients as compared to controls (P < 0.05). Further, serum NTx level was significantly higher in CD patients who were receiving IFX as compared to CD patients who were not receiving IFX (P < 0.01).

CONCLUSIONS

A lower BMD and higher bone metabolism markers were found in CD patients as compared to controls or UC patients. A significant increased serum level of NTx, a biochemical marker of increased bone resorption, was observed in CD patients during IFX therapy.

Review article: the effects of antitumour necrosis factor-α on bone metabolism in inflammatory bowel disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of osteoporosis. A number of studies have emerged in recent years indicating that tumour necrosis factor (TNF) blockade appears to have a beneficial effect on bone mineral density (BMD) in IBD patients.

AIMS

To provide a review of the available data regarding the effect of the currently licensed anti-TNF-α therapies on bone metabolism and BMD in IBD patients.

METHODS

A Medline search was performed using the search terms 'infliximab', 'bone metabolism', 'IBD', 'BMD', 'bone markers', 'adalimumab', 'bone disease', 'Crohn's disease' and 'ulcerative colitis'.

RESULTS

Infliximab has a beneficial effect on bone turnover markers in Crohn's disease (CD) patients in the short term. The longest study to date comprising 24 CD patients showed an overall improvement in two bone formation markers - b-alkaline phosphatase (P = 0.022) and osteocalcin (P = 0.008) at 4 months post-treatment. Moreover, the largest study to date comprising 71 CD patients showed significant improvement in sCTx, a bone resorption marker (P = 0.04) at week-8 post-treatment. There is little data looking at the effect of anti-TNF-α therapy on bone metabolism in ulcerative colitis. Moreover, the long-term effects of anti-TNF-α therapy on bone structure and fracture risk in IBD patients are currently not known. The effect of cessation of anti-TNF-α therapy on bone metabolism is also unknown.

CONCLUSION

Properly controlled long-term trials are needed to fully evaluate the impact of TNF blockade on bone mineral density.

Association of vitamin K deficiency with bone metabolism and clinical disease activity in inflammatory bowel disease

OBJECTIVE

Inflammatory bowel disease (IBD) is a chronic inflammatory process in the digestive tract and patients with IBD develop osteopenia. Although vitamins K and D are important for maintaining bone health and inhibiting inflammation, their roles in patients with IBD are not clear. We investigated the roles of vitamins K and D in the bone health and inflammation in patients with IBD.

METHODS

Bone mineral density (BMD) of patients with IBD (Crohn's disease [CD], n = 47, and ulcerative colitis [UC], n = 40) was measured with dual-energy X-ray absorptiometry. Vitamin K and D levels of patients with IBD and healthy volunteers (n = 41) were evaluated by measuring serum undercarboxylated osteocalcin and 1,25 dihydroxyvitamin D, respectively. Clinical activity index was evaluated in patients with CD and UC.

RESULTS

BMD was low in patients with CD and UC. Serum undercarboxylated osteocalcin levels were significantly higher in patients with CD, but not with UC, compared with healthy subjects, indicating that bone vitamin K is insufficient in patients with CD. The levels of undercarboxylated osteocalcin were significantly correlated with the clinical activity index of CD, although they were not correlated with BMD. The levels of 1,25 dihydroxyvitamin D were significantly lower in patients with CD and UC than in healthy subjects. The levels of 1,25 dihydroxyvitamin D were inversely correlated with BMD in patients with UC and were not correlated with the clinical activity index of CD.

CONCLUSION

Vitamins K and D are insufficient in patients with IBD. Insufficiency of vitamin K is suggested to be associated with inflammatory processes of CD.

A double-blind placebo-controlled study of intravenous clodronate for prevention of steroid-induced bone loss in inflammatory bowel disease

BACKGROUND & AIMS

Osteoporosis is common in patients with inflammatory bowel disease (IBD). Corticosteroids induce a rapid and important bone loss. Clinical trials have shown oral bisphosphonates to effectively prevent steroid-induced bone loss. However, patients with IBD have been excluded from most of these studies because of potential digestive adverse events. Clodronate is a non-amino-bisphosphonate available in intravenous form without expected digestive (as oral bisphosphonates) or proinflammatory (as amine bisphosphonates) side effects. Our aim was to assess the efficacy of intravenous clodronate in preventing steroid-induced bone loss.

METHODS

A 12-month, double-blind, randomized, placebo-controlled trial was conducted in IBD patients beginning a steroid therapy. Sixty-seven patients (median disease duration, 38 mo; range, 1-240 mo) were randomized to receive one infusion per 3 months of either intravenous clodronate (900 mg, n = 33) or placebo. All the patients received calcium (1 g/day) and vitamin D (800 IU/day). The main outcome was the change in lumbar bone mineral density (BMD) between baseline and 1 year. Secondary outcomes included change in femoral neck BMD and adverse events.

RESULTS

After 1 year, there was no change in BMD in the clodronate group, neither at the spine (-0.2%, not significant) nor at the femoral neck (2.3%, NS). In contrast, there was a significant decrease in lumbar spine (-2.0%, P = .0018) and femoral neck (-1.7%, P = .045) BMD in the placebo group. Tolerance to treatment was good.

CONCLUSIONS

Intravenous clodronate is effective in the prevention of bone loss induced by steroids in patients with IBD.

The effect of marine oil-derived n-3 fatty acids on transepithelial calcium transport in Caco-2 cell models of healthy and inflamed intestines

Marine oil-derived n-3 fatty acids have been shown to stimulate intestinal Ca absorption in animal studies, but the effects of such fatty acids on Ca absorption in human subjects are relatively unknown. In particular, n-3 fatty acids may be of therapeutic value for some Crohn's disease patients who experience Ca malabsorption. Therefore, the aim of the present study was to investigate the effect of 20 : 5n-3 and 22 : 6n-3 on transepithelial Ca transport across monolayers of healthy Caco-2 cells as well as of TNF-α-treated Caco-2 cells (an in vitro model of Crohn's disease). Caco-2 cells were seeded onto permeable filter supports and allowed to differentiate into monolayers, which were treated with 80 μm-20 : 5n-3, 80 μm-22 : 6n-3, or 40 μm-20 : 5n-3+40 μm-22 : 6n-3 for 6 or 8 d, with or without co-treatment with TNF-α (10 ng/ml) (n 11–15 monolayers per treatment). On day 16, transepithelial and transcellular transport of 45Ca and fluorescein transport (a marker of paracellular diffusion) were measured. Treatment of healthy and inflamed Caco-2 cells with 20 : 5n-3, 22 : 6n-3 and both fatty acids combined for 8 d significantly (P < 0·005–0·01) increased total transepithelial Ca transport compared with that in control, effects which were mediated by an enhanced rate of transcellular Ca transport. The effects of n-3 fatty acids on Ca absorption after 6 d were less clear-cut. In conclusion, the present in vitro findings highlight the need to investigate the effect of marine oil-based n-3 fatty acids on Ca absorption in vivo in studies of healthy human subjects as well as of Crohn's disease patients.

Altered levels of biochemical indices of bone turnover and bone-related vitamins in patients with Crohn's disease and ulcerative colitis

BACKGROUND

The pathogenesis of inflammatory bowel disease-associated osteopenia may be related to pathological rates of bone turnover; however, the literature shows mixed results.

AIM

To compare bone biomarkers in inflammatory bowel disease patients (Crohn's disease: n = 68, and ulcerative colitis: n = 32, separately) with age- and sex-matched healthy controls.

SUBJECTS

Patients and controls were recruited from Cork University Hospital and Cork City area, respectively.

RESULTS

Relative to that in their respective controls, Crohn's disease (n = 47) and ulcerative colitis (n = 26) patients (i.e. excluding supplement users) had significantly (P < 0.05-0.001) higher serum undercarboxylated osteocalcin (by 27% and 63%, respectively) and bone-specific alkaline phosphatase (by 15% and 21%, respectively) and urinary Type I collagen cross-linked N-telopeptides concentrations (by 87% and 112%, respectively). Relative to that in their respective controls, Crohn's disease and ulcerative colitis patients had significantly (P < 0.01) lower serum total osteocalcin (by 20% and 42%, respectively) and 25-hydroxyvitamin D (by 37% and 42%, respectively), while serum parathyroid hormone levels were similar. In the combined patient group (n = 100), undercarboxylated osteocalcin was positively associated with bone markers.

CONCLUSIONS

Both Crohn's disease and ulcerative colitis patients have altered bone turnover relative to that in healthy controls.

Seasonality of vitamin D status and bone turnover in patients with Crohn's disease

BACKGROUND

While winter-time vitamin D deficiency has been well-documented in Crohn's disease patients, less is known about vitamin D status during summertime and whether a seasonal variation exists in bone turnover.

AIMS

To compare vitamin D status and bone turnover markers in Crohn's disease patients with age- and sex-matched controls during late-summer and late-winter.

SUBJECTS

Crohn's disease patients (n = 44; mean age 36.9 years, currently in remission) and matched controls (n = 44) were recruited from Cork University Hospital and Cork City area, respectively.

METHODS

Bloods were analysed for 25-hydroxyvitamin D, parathyroid hormone, bone-specific alkaline phosphatase, osteocalcin and urine analysed for N-telopeptides of type 1 collagen.

RESULTS

Serum 25-hydroxyvitamin D concentrations were significantly (P < 0.003) lower in Crohn's disease patients than in control subjects during both seasons. In Crohn's disease patients, serum 25-hydroxyvitamin D concentrations were lower (P < 0.0001) whereas serum parathyroid hormone, osteocalcin and bone-specific alkaline phosphatase and urinary N-telopeptides of type 1 collagen levels were higher (P < 0.001) during late-winter than late-summer.

CONCLUSION

There were notable seasonal variations in vitamin D status and bone turnover markers in Crohn's disease patients. The impact of winter decline in vitamin D status and increase in bone turnover on long-term risk of osteopenia/osteoporosis in Crohn's disease patients is unclear.

Osteoporosis and Crohn's disease

Osteoporosis and osteopenia have been reported frequently in patients with inflammatory bowel disease, most notably Crohn's disease.

OBJECTIVES

To determine the prevalence and risk factors of osteoporosis in patients with Crohn's disease.

METHODS

Prospective study of 56 patients with Crohn's disease, 34 men and 22 women with a mean age of 32 +/- 10.4 years (18-54 years) and no history of disorders known to influence bone metabolism. Dual-energy X-ray absorptiometry measurements of bone mineral density (BMD) were obtained at the femoral neck and lumbar spine. A multivariate model including those factors significantly associated with low BMD in the univariate analysis was used to identify independent risk factors.

RESULTS

Osteoporosis was found in 35.7% and osteopenia in 23.2% of patients. Low BMD was significantly associated with low body mass index (BMI), colonic involvement, and glucocorticoid therapy. Low BMI was an independent risk factor for low BMD. Malnutrition with BMI < or =18 kg/m2 was noted in 21 patients, of whom 76.2% had low BMD values, as compared to 48.6% of the patients whose BMI was >18 kg/m2 (P = 0.03, odds ratio = 3.4).

CONCLUSION

Among risk factors for bone loss in patients with Crohn's disease, malnutrition plays a prominent role that deserves attention when planning treatment programs.

Vitamin K status in patients with Crohn's disease and relationship to bone turnover

BACKGROUND

There is a high prevalence of osteopenia among patients with Crohn's disease (CD). There is some evidence that a deficiency of certain bone-active nutrients (including vitamins K and D) may have a partial role in this bone loss.

AIMS

To compare the intake and the status of vitamin K in CD patients, currently in remission, with age- and sex-matched controls, and furthermore to investigate the relationship between vitamin K status and bone turnover in these patients.

SUBJECTS

CD patients (n = 44; mean age: 36.9 yr) and matched controls (n = 44) were recruited from the Cork University Hospital and Cork City area, respectively.

METHODS

Bloods were analyzed for the total and undercarboxylated (Glu)-osteocalcin and urine analyzed for cross-linked N-telopeptides of type I collagen (NTx). Vitamin K(1) intake was estimated by food frequency questionnaire.

RESULTS

Vitamin K(1) intake in CD patients tended to be lower than that of controls (mean (SD), 117 (82) vs 148 (80) mug/d, respectively; p= 0.059). Glu and NTx concentrations in CD patients were higher than controls (mean (SD), 5.1 (3.1) vs 3.9 (2.1) ng/ml, respectively; p= 0.03 for Glu; and 49 (41) vs 25.8 (19.5) nM BCE/mM creatinine, respectively; p= 0.001 for NTx). In CD patients, Glu was significantly correlated with NTx (r= 0.488; p < 0.001), even after controlling for age, gender, vitamin D status, calcium intake, and corticosteroid use.

CONCLUSION

Vitamin K status of CD patients was lower than that of the healthy controls. Furthermore, the rate of bone resorption in the CD was inversely correlated with vitamin K status, suggesting that it might be another etiological factor for CD-related osteopenia.

Rapid improvement of bone metabolism after infliximab treatment in Crohn's disease

BACKGROUND

Crohn's disease is associated with low bone mineral density and altered bone metabolism.

AIM

To assess the evolution of bone metabolism in Crohn's disease patients treated with infliximab.

METHODS

We studied 71 Crohn's disease patients treated for the first time with infliximab for refractory Crohn's disease. Biochemical markers of bone formation (type-I procollagen N-terminal propeptide, bone-specific alkaline phosphatase, osteocalcin) and of bone resorption (C-telopeptide of type-I collagen) were measured in the serum before and 8 weeks after infliximab therapy and compared with values in a matched healthy control group.

RESULTS

Eight weeks after treatment with infliximab, a normalization of bone markers was observed with a median increase in formation markers of 14-51% according to marker and a lower but significant decrease in resorption marker (median 11%). A clinically relevant increase in bone formation markers was present in 30-61% of patients according to the marker. A clinically relevant decrease in C-telopeptide of type-I collagen was present in 38% of patients. No association was found with any tested demographic or clinical parameter.

CONCLUSION

Infliximab therapy in Crohn's disease may rapidly influence bone metabolism by acting either on bone formation or bone resorption. This improvement seems to be independent of clinical response to infliximab.

Beyond deficiency: potential benefits of increased intakes of vitamin K for bone and vascular health

Vitamin K is well known for its role in the synthesis of a number of blood coagulation factors. During recent years vitamin K-dependent proteins were discovered to be of vital importance for bone and vascular health. Recommendations for dietary vitamin K intake have been made on the basis of the hepatic requirements for the synthesis of blood coagulation factors. Accumulating evidence suggests that the requirements for other functions than blood coagulation may be higher. This paper is the result of a closed workshop (Paris, November 2002) in which a number of European vitamin K experts reviewed the available data and formulated their standpoint with respect to recommended dietary vitamin K intake and the use of vitamin K-containing supplements.

Patients With Eating Disorders

PURPOSE

To analyze fracture risk and bone mineral density in patients with eating disorders (anorexia nervosa, bulimia nervosa, and other eating disorders).

DESIGN

Clinical overview.

FINDINGS

Bone mineral density is decreased and fracture risk increased in patients with anorexia nervosa. In patients with bulimia nervosa, bone mineral is only marginally decreased and fracture risk marginally increased. In patients with other eating disorders (eating disorders not otherwise specified), bone mineral density is decreased and fracture risk increased.

CONCLUSIONS

Fracture risk is increased in patients with eating disorders. An eating disorder should be suspected in severely underweight young individuals (primarily girls) presenting with fractures, especially low-energy fractures.

Bone loss associated with gastrointestinal disease: prevalence and pathogenesis

Decreased bone mineral density is a frequent finding in gastrointestinal disease. Factors contributing to this are (1) malabsorption of vitamin D, calcium and possibly vitamin K and other nutrients; (2) treatment with glucocorticoids; (3) inflammatory cytokines in inflammatory bowel disease; and (4) hypogonadism induced by gastrointestinal disease. A low bone mineral density has been reported in (1) patients who have undergone gastrectomy (27-44% with Z-scores of < -1); (2) pernicious anaemia; (3) coeliac disease (8-22% with Z-scores of < -2); (4) Crohn's disease (mean 32-38% with Z-scores of < -1); and (5) ulcerative colitis (mean 23-25% with Z-scores of < -1). Reduced bone mineral density is thus prevalent in these individuals and is compounded by age related bone loss, leading to the development of severe bone disease in some patients.

Population demographics and socioeconomic impact of osteoporotic fractures in Canada

Through a survey of the literature and an analysis of selected national and regional statistics, a review of the incidence of osteoporosis and its consequences was performed. Results illustrate that the consequences of osteoporosis are preventable and should sensitize clinicians to the importance of early detection and the identification of risk factors for disease prevention and to early treatment once disease has been established. A marked increase in the annual incidence of hip fractures in all Canadians is noted. Whereas the incidence was less than 20,000 in 1981, the incidence of hip fracture grew to 27,342 in 1995, with 73% occurring in women. It is estimated that in Canada at least one in four women older than 50 years will have one or more osteoporosis-related fractures in their lifetimes. The consequences of these fractures are considerable, both for patients and healthcare services. Only half of all victims regain total autonomy, and the total direct costs in Canada stemming from osteoporosis are estimated to be $1.3 billion per year.