Abstract
Objective: We examined the association between vitamin K status and physical functioning over 13 years in the Longitudinal Aging Study Amsterdam. Study design: Longitudinal cohort study of 633 community-dwelling adults from the Longitudinal Aging Study Amsterdam (LASA) aged 55–65 years (54% women). Main outcome measures: At baseline (2002–2003), plasma desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) was measured with a sandwich ELISA as a marker of vitamin K status. The outcome measures handgrip strength, calf circumference, self-reported functional limitations and functional performance were obtained at baseline and four follow-up examinations. We used generalized estimating equations to determine the relationship between dp-ucMGP tertiles and the various outcome measurements after adjusting for potential confounders. The lowest dp-ucMGP tertile reflects a high vitamin K status and was the reference. Results: Mean dp-ucMGP was 376 ± 233 pmol/L and mean follow-up was 11.1 years. Participants showed a decline in the outcome measures over time. Compared with the lowest tertile, the highest dp-ucMGP tertile had: lower handgrip strength, 1.1 kg (95% confidence interval (−2.1, −0.1; P-trend <0.001); smaller calf circumference, −0.5 cm (−0.9 −0.1; P-trend = 0.018); and, only among women, a 0.7-point poorer functional performance score (−1.1, −0.3; P-interaction = 0.002). Dp-ucMGP was not related to self-reported functional limitations. No interaction effects between time and dp-ucMGP were observed. Conclusions: Low vitamin K status was associated with lower handgrip strength, smaller calf circumference, and, in women only, with poorer functional performance score. A low vitamin K status was however not related to the 13-year decline in these measures.
Original language | English |
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Pages (from-to) | 73-79 |
Number of pages | 7 |
Journal | Maturitas |
Volume | 113 |
Early online date | 28 Apr 2018 |
DOIs | |
Publication status | Published - 1 Jul 2018 |
Funding
LASA is largely supported by the Netherlands Ministry of Health, Welfare and Sports, Directorate of Long-Term Care . We are extremely grateful to all LASA participants and the fieldwork team for their ongoing commitment to the study. The dp-ucMGP measurements were funded by FrieslandCampina, a dairy company . The funders had no role in any part of the study.
Keywords
- Matrix gla protein
- Physical decline
- Physical functioning
- Vitamin K status