Vitamin K status and mobility in older adults

Relation

Shea Mk, Kritchevsky SB, Loeser RF, Stand Sl. Vitamin K status and exposure to mobility and disability in older adults: the study on health, aging and body composition [Published Online Ahead of Print May 6, 2019]. (Link away).

Study goal

To determine whether vitamin K deficiency (as a phyllochinone) can be a risk factor for restricted mobility and disability in older adults.

Draft

Prospective longitudinal cohort study

Participant

The study included 1,323 participants (635 men, 688 women) with an average age of 74.6 ± 2.8 years. 40 % were African Americans, 60 % Caucasians.

Study parameters assessed

1. Objective parameters:

a. Output splasm phyllochinone (vitamin K) and subcarboxylated matrix glycoprotein (UCMGP; mirrors correlate the vitamin K status) conversely)
b. Serum triglycerides
c. Interleukin-6 (IL-6)
d. Glomerular filtration rate (GFR)

2. Subjective parameters:

a. Index for healthy eating (HEA)
b. Mobility restriction: Defined as 2 successive semi -annual reports about difficulties either to go ¼ mile or increase 10 stages without resting.
c. Mobility restriction: defined as 2 successive semi -annual reports of great difficulties or inability to go ¼ mile or increase 10 stages without resting.

Primary result measurements

1. ucMGP
2. Mobilitätseinschränkung
3. Mobilitätseinschränkung

Key insights

Plasma phyllochinone (vitamin K₁) was positive with triglycerids and the hot and vice ll-6 and knee pain.

Incidentally, plasma ucMGP was positively associated with triglycerides and IL-6. Independently, ucMGP was inversely associated with estimated GFR. African American participants were more likely to have lower ucMGP.

When analyzes of plasma phylloquinone and mobility were restricted to the subgroup of participants in whom ucMGP was measured (n = 716), the association between plasma phylloquinone and mobility impairment was similar, but the association with mobility disability was attenuated.

In a cross-sectional analysis, participants with less than 0.5 nmol/L plasma phylloquinone were 1.49 times more likely to have a mobility limitation (odds ratio [OR]: 1.49; 95% confidence interval [CI]: 1.04-2.13, fully adjusted) and almost twice as likely to have a mobility limitation (OR: 1.95; 95% CI: 1.08-3.54, fully adjusted) compared to those with at least 1.0 nmol/L.

According to data from the 2011-2012 National Health and Nutrition Examination Survey (NHANES), an average of 57% of men and 37.5% of women do not consume even the minimum amount of vitamin K per day.¹

The likelihood of mobility restriction and disability does not differ significantly between those with 0.5–1.0 NMOL/L phyllochinone and those with at least 1.0 NMOL/L (OR: 1.19; 95 % KI: 0.87–1.63 for mobility restriction; OR: 1.65; 95 % KI: 0.97-2,81 for mobility restriction, both full Adjusted).

The likelihood of having a mobility limitation or disability did not differ significantly between ucMGP tertiles. Compared to tertile 1, the ORs for mobility limitations were 1.16 for tertile 2 (95% CI: 0.77–1.74) and 1.42 for tertile 3 (95% CI: 0.93–2.17). The odds for mobility limitation (also compared to tertile 1) were 0.88 for tertile 2 (95% CI: 0.44–1.74) and 1.62 for tertile 3 (95% CI: 0.84–3.13), all fully adjusted.

Practice implications

This study is one of two studies to date that have examined the vitamin K status and frailty in older adults. An earlier study from 2016 examined the connection between the non-phosphorylated and non-carboxylated isoform of MGP (DP-UCMGP), another marker for vitamin K status, and frailty.¹

Nutritional deficiencies are known risk factors for chronic disease, functional impairment and mortality. Therefore, understanding how nutrients influence disease onset and progression is important to inform public health policy, teach clinicians how to identify and properly screen patients at risk, and develop treatments that potentially address and reverse underlying nutritional deficiencies.

In this study, researchers found that older adults with plasma phylloquinone levels less than 0.5 nmol/L were more likely to develop mobility limitation and disability than those with at least 1.0 nmol/L. However, after adjustment for knee pain, the risk of mobility impairment was not significantly different between patients with plasma phylloquinone less than 0.5 nmol/L and those with at least 1.0 nmol/L.

Plasma ucMGP was not associated with mobility impairment. However, plasma ucMGP was associated with mobility limitation, such that those in the middle ucMGP tertile were more likely to develop mobility limitation than those in the lowest tertile, but there was no difference in the incidence of mobility limitation between those in the highest and lowest tertiles.

There are several challenges in interpreting and clinical use of these results. First, the association does not mean causality. Mobility is a complex mechanical process under neurological, musculoskeletal and hormonal control. Reduction to a single nutrient can overlook more basic reasons why a patient has problems.

Second, the vitamin K status, measured by surrogate markers like UCMGP, is not a simple estimate. An abnormal lipid profile can influence the results, as stated in the present study. While UCMGP decreases with the consumption of vitamin K, the production of MGP is regardless of vitamin K. The researchers have not measured MGP or given a UCMGP-to-MGP ratio, which would have been more revealing.

The challenge with surrogate markers is important for clinicians to understand because we often discuss, recommend, or test surrogate markers. The most common vitamin K-dependent surrogate marker that has been clinically tested is undercarboxylated osteocalcin (ucOC).

This marker has been inversely associated with osteoporosis; However, as the authors of the present study emphasize, we do not yet have a clinical definition of vitamin K deficiency based on surrogate markers because the relevance of different thresholds for clinical endpoints has not been widely investigated. Furthermore, according to a 2016 review by Shea and Booth published in the magazineNutrients"In contrast to other nutrients, there is no single biomarker that is considered the gold standard for vitamin K status."²

The present study is inadequate insofar as it did not measure UCMGP and Plasma vitamin K in serial, which would have resulted in a better estimate of the vitamin K status. The study participants also did not fill a questionnaire for the frequency of food in order to estimate their vitamin K intake from food.

As an essential nutrient, vitamin K (as a phyllochinone that was measured in this study) can only be absorbed through food or nutritional supplements. It is important that a concentration of less than 0.5 NMOL/L, according to the researchers, is associated with reduced mobility, a vitamin K intake through the food of less than half of the recommended adequate supply (AI). The AI ​​for vitamin K for adults is 90 micrograms for women and 120 micrograms for men.³

How often does it happen that people do not consume the active ingredient for vitamin K? According to data from the National Health and Nutrition Examination Survey (Nhanes) from 2011-2012, an average of 57 % of men and 37.5 % of women do not even take the minimum of vitamin K a day.⁴

Therefore, vitamin K status, like the status of other essential nutrients, should be evaluated in the context of an individual's overall dietary pattern. Plants, particularly green leafy vegetables, are the primary source of dietary vitamin K (phylloquinone) in the United States.

In view of the spread of poor nutrition in the United States, the control of the nutritional status is important when attempts are made to correlate a clinical end point with a single nutrient. An estimated 56% of adults in the United States do not consume the minimum need for magnesium.⁵15 % consume less than half of the recommended daily dose (RDA) for vitamin C, 10 % consume fewer than half of the RDA for vitamin E and 18 % consume less than half of the RDA for zinc.⁶

In addition to not correcting dietary habits, researchers did not evaluate or correct other potential nutritional deficiencies known to affect mobility, such as: B. Vitamin D. Vitamin D deficiency is associated with loss of muscle mass.^7.8The weakness,⁹and reduced function of the lower extremities.¹⁰Finally, they did not screen the patients for sarcopenia, which can also affect mobility.¹¹

Because biochemistry involves a network of interactions between biochemical pathways, control of overall nutritional status is important.

Research on how nutrients can correlate with diseases is important in order to advance the influence of nutrition on health and medicine. In order for research in this area to have the greatest clinical influence, future studies should correct nutritional status, evaluate the nutritional status based on laboratory tests and control variables, of which we already know that they contribute to reduced mobility and impairment.