Seasonal variation of serum alpha- and beta-cryptoxanthin and 25-OH-vitamin D(3) in women with osteoporosis

Seasonal Variation and Global Public Interest in the Internet Searches for Osteoporosis

Background

To ascertain the seasonal pattern and global public interest in osteoporosis by evaluating search term popularity changes of the disease over a decade.

Methods

We applied Google Trends to retrieve search popularity scores for the term “osteoporosis” between January 01, 2004, and December 31, 2019. Cosinor analyses were conducted to examine the seasonality of osteoporosis, and analysis on osteoporosis-related topics including hot topics and rising-related topics was also performed.

Results

The cosinor analyses demonstrated a statistically significant seasonal variation in relative search volume of the “osteoporosis” in the world (p = 0.0083), USA (p < 0.001), UK (p < 0.001), Canada (p < 0.001), Ireland (p < 0.001), Australia (p < 0.001), and New Zealand (p < 0.001), with a peak in the late winter months and trough in the summer months. The peaks in late winter and valley in summer presented an approximately 6-month difference between hemispheres. The top 11 rising topics were denosumab, FRAX, hypocalcaemia, zoledronic acid, ibandronic acid, osteomyelitis, osteopenia, osteoarthritis, bone, calcium, and bone density.

Conclusions

Google search query volumes related to osteoporosis follow strong seasonal patterns with late winter peaks and summer troughs. Further studies aimed at elucidating the possible mechanisms behind seasonality in osteoporosis are needed. Moreover, Internet data including the top rising topics may alert physicians to strengthen the propaganda of osteoporosis timely, so as to further promote the development of public health interventions.

Absorption, metabolism, and functions of β-cryptoxanthin

β-Cryptoxanthin, a carotenoid found in fruits and vegetables such as tangerines, red peppers, and pumpkin, has several functions important for human health. Most evidence from observational, in vitro, animal model, and human studies suggests that β-cryptoxanthin has relatively high bioavailability from its common food sources, to the extent that some β-cryptoxanthin-rich foods might be equivalent to β-carotene-rich foods as sources of retinol. β-Cryptoxanthin is an antioxidant in vitro and appears to be associated with decreased risk of some cancers and degenerative diseases. In addition, many in vitro, animal model, and human studies suggest that β-cryptoxanthin-rich foods may have an anabolic effect on bone and, thus, may help delay osteoporosis.

Fibroblast Growth Factor-23 and Vitamin D Metabolism in Subjects with eGFR ≥60 ml/min/1.73 m²

BACKGROUND/AIMS

Fibroblast growth factor (FGF)-23 and parathyroid hormone (PTH) are both potent phosphaturic hormones. Since they exert opposite effects on vitamin D metabolism, the measurement of 3 vitamin D metabolites; 25-hydroxyvitamin D (25-OH-D), 1,25-dihydroxyvitamin D (1,25(OH)2D), and 24,25-dihydroxyvitamin D (24,25(OH)2D), allows the distinction of the effects of FGF-23 from those of PTH. The aim of this study was to elucidate which factor, FGF-23 or PTH, plays a more important role in the regulation of vitamin D metabolites in subjects with estimated glomerular filtration (eGFR) ≥60 ml/min/1.73 m(2).

METHODS

Subjects with eGFR ≥60 ml/min/1.73 m(2) (n = 20) were enrolled and their serum levels of FGF-23, intact PTH, and vitamin D metabolites were determined.

RESULTS

Serum FGF-23 correlated inversely with 1,25(OH)2D (r = -0.717, p = 0.0004) and the 1,25(OH)2D/25-OH-D ratio (r = -0.518, p = 0.019), compared with a significant positive correlation between serum intact PTH and the 1,25(OH)2D/25-OH-D ratio (r = 0.562, p = 0.010). Multiple regression analyses revealed serum FGF-23 as a significant factor that was associated with serum 1,25(OH)2D (β = -0.593, p = 0.018), 1,25(OH)2D/25-OH-D ratio (β = -0.521, p = 0.025), and the 24,25(OH)2D/1,25(OH)2D ratio (β = 0.632, p = 0.008), and intact PTH as a significant factor associated with the 1,25(OH)2D/25-OH-D ratio (β = 0.445, p = 0.028).

CONCLUSIONS

This study demonstrated that, even in subjects with eGFR ≥60 ml/min/1.73 m(2), FGF-23 might play an important role in the regulation of vitamin D metabolism. In addition to the established role of PTH, the association between FGF-23 and indices of vitamin D metabolism suggested the potential role of FGF-23 on phosphate metabolism in such patients.

Role of carotenoid β-cryptoxanthin in bone homeostasis

Bone homeostasis is maintained through a balance between osteoblastic bone formation and osteoclastic bone resorption. Aging induces bone loss due to decreased osteoblastic bone formation and increased osteoclastic bone resorption. Osteoporosis with its accompanying decrease in bone mass is widely recognized as a major public health problem. Nutritional factors may play a role in the prevention of bone loss with aging. Among various carotenoids (carotene and xanthophylls including beta (β)-cryptoxanthin, lutein, lycopene, β-carotene, astaxanthin, and rutin), β-cryptoxanthin, which is abundant in Satsuma mandarin orange (Citrus unshiu MARC.), has been found to have a stimulatory effect on bone calcification in vitro. β-cryptoxanthin has stimulatory effects on osteoblastic bone formation and inhibitory effects on osteoclastic bone resorption in vitro, thereby increasing bone mass. β-cryptoxanthin has an effect on the gene expression of various proteins that are related osteoblastic bone formation and osteoclastic bone resororption in vitro. The intake of β-cryptoxanthin may have a preventive effect on bone loss in animal models for osteoporosis and in healthy human or postmenopausal women. Epidemiological studies suggest a potential role of β-cryptoxanthin as a sustainable nutritional approach to improving bone health of human subjects. β-Cryptoxanthin may be an osteogenic factor in preventing osteoporosis in human subjects.

[Has vitamin D(3) dosage improved in Spain? Current levels in a population sample]

INTRODUCTION

According to current classifications, the metabolite of greatest clinical interest to evaluate vitamin D(3) dosage is 25-hydroxyvitamin D(3) with a reference interval of approximately 10-70ng/ml, although many authors consider values of approximately 40ng/ml or 100nmol/l to be desirable. According to these definitions, three out of four people in Spain would have vitamin D(3) deficiency.

MATERIAL AND METHOD

The RIA-CT technique was used for diagnosis of 25(OH)D(3) to determine the population status. Subsequently, a case-control study was performed to evaluate the relationship between distinct diseases and vitamin D(3) deficiency.

RESULTS

A total of 73.2% of the cases were found to be within the range considered acceptable, according to the present classification. One hundred percent of the control group and healthy menopausal women who did not receive any kind of vitamin supplement had levels of 40 ng/ml or more.

DISCUSSION AND CONCLUSIONS

Our results indicate that the prior situation of a high prevalence of vitamin D(3) deficiency has improved and that levels are now acceptable in 26.8% of the population, with a mean value of 46.2 ng/ml, considering 10-70 ng/ml as the reference range.