The well-established roles of vitamin D in bone calcium metabolism make vitamin D a highly influential factor that can be used for the prevention and treatment of the common musculoskeletal disorder osteoarthritis (OA).
In addition, vitamin D has been shown to have benefits in many non-skeletal diseasessuch as cardiovascular disease (CVD), diabetes and cancer, through its effects of reducing inflammation, antiproliferative activity, antioxidant activity, etc.
Although the benefit of vitamin D in reducing mortality has been reported in the general population and in diabetic patients, only a few studies have focused on such a relationship for OA patients.
Therefore, the present study aimed to assess whether serum 25(OH)D concentrations were associated with all-cause and cause-specific mortality in OA patients from NHANES III (National Health and Nutrition Examination Survey). in the US) and the newly published NHANES 2001–2018 database.
This study concludes that OA patients with sufficient serum 25(OH)D were associated with a significantly lower risk of all-cause mortality and CVD than those with lower 25(OH)D levels, suggesting a beneficial role. of vitamin D in the long term. -basic term.
“Furthermore, relatively lower hazard ratios (HRs) were observed in men than in women, highlighting the need to develop gender-specific therapeutic strategies for patients with OA, especially postmenopausal women.” says the report.
Results
In this analysis, 4570 patients with OA were included, with a median follow-up of 7.6 years. Approximately 65.53% of the patients were women and the mean age was 61.82 ± 12.94 years.
A total of 16.54% of the patients had vitamin D deficiency (<50 nmol/L) and 48.15% vitamin D insufficiency (<75 nmol/L). As of the census day of December 31, 2019, 1,388 OA patients died, including 427 (30.8%) from CVD, 268 (19.3%) from cancer, and 693 (49.9%) from other causes.
On a continuous scale, an L-shaped association was found for all-cause mortality, and the serum concentration of 25(OH)D associated with the lowest risk of all-cause mortality was approximately 84.50 nmol/ L. An inverse association was found for CVD-specific mortality.
However, such associations were not significant for cancer-specific mortality.
Methods
NHANES is a large-scale periodic program that collects nationally representative health-related data from non-institutionalized citizens in the United States.
Here, data from NHANES III (from 1988 to 1994) and NHANES 2001–2018 were used and only respondents (aged 18+) with self-reported OA were included.
The authors collected all serum 25(OH)D data and corresponding mortality information.
The authors point out several limitations of the study. First, due to the lack of repeated vitamin D measurements, they were unable to determine associations of dynamic vitamin D status with mortality. Second, the inclusion of OA patients was based on a simple question, “Have you ever been told by doctors that you have OA,” rather than medical records. Another limitation was the limited statistical power to detect associations between 25(OH)D and cancer-specific mortality, given the low frequency of cancer deaths.
Furthermore, the studies showed that the role of vitamin D in cancer incidence and survival and at different cancer sites might be different. Therefore, where feasible, future studies evaluating the effect of vitamin D on different cancer sites are warranted. Finally, due to study design, the authors were unable to directly infer causality of vitamin D with mortality in OA patients.
“Theoretically, this question can be addressed using randomized controlled trials and Mendelian randomization analyses.” the report says, “Which unfortunately we were not able to do in this study. Future studies evaluating possible causal associations are vital to elucidate the long-term effect of vitamin D (such as reducing mortality) in patients with OA.”
The role of vitamin D
Bone diseases are one of the leading causes of death in the elderly [24]and it is widely known that vitamin D helps the body absorb and use calcium, protecting the bones [25].
Serum vitamin D is first converted to the hormone calcitriol (known as “active vitamin D”), which can promote calcium absorption, for example, by acting on the nuclei of mucosal cells in the small intestine. [26]. Calcium then combines with other minerals to form hard crystals, giving bones strength and structure.
In addition, calcium also has benefits in other systems of the body, such as lowering blood pressure and cholesterol levels, preventing tooth loss, etc. [27].
The benefits mentioned above, whether related to bones, endocrine or dental, have an essential impact in reducing mortality in adulthood. In contrast, in a situation of vitamin D deficiency, the body has to take calcium from its stores in the skeleton. Weakened existing bone leads to less favorable survival [24].
Font: nutrients
https://doi.org/10.3390/nu14214629 (registering DOI)
“Vitamin D status and risk of all-cause and cause-specific mortality in patients with osteoarthritis: results from NHANES III and NHANES 2001-2018”
Wang, J.; Fan, J.; Yang, Y.; Moazen, S.; Chen, D.; Sol, L.; He, F.; li, and.