Dietary magnesium intake, serum high sensitivity C-reactive protein and the risk of incident knee osteoarthritis leading to hospitalization-A cohort study of 4,953 Finns

Objectives To study whether low dietary magnesium (Mg) intake and serum high sensitivity C-reactive protein (hs-CRP) predict the development of clinical knee osteoarthritis (OA). Methods The cohort consisted of 4,953 participants of a national health examination survey who were free of knee and hip OA at baseline. Information on the incidence of knee OA leading to hospitalization was drawn from the National Care Register for Health Care. During the follow-up of 10 years, 123 participants developed incident knee OA. Dietary magnesium intake was assessed on the basis of a food frequency questionnaire from the preceding year. We used Cox's proportional hazards model to estimate the strength of the association between the tertiles of dietary Mg intake and incident knee OA, adjusted for baseline age, gender, energy intake, BMI, history of physical workload, leisure time physical activity, injuries, knee complaints, the use of Mg supplements, and serum hs-CRP levels. Results At baseline, dietary Mg intake was inversely associated with serum hs-CRP even after adjustment for all the potential confounding factors. During the follow-up, the adjusted hazard ratios (with their 95% confidence intervals) for incident knee OA in dietary Mg intake tertiles were 1.00, 1.28 (0.78-2.10), and 1.38 (0.73-2.62); the p value for trend was 0.31. Serum hs-CRP level at baseline did not predict incident knee OA. Conclusions The results do not support the hypothesis that low dietary Mg intake contributes to the development of clinical knee OA, although Mg intake is inversely associated with serum hs-CRP level.Peer reviewe

Systemic and dietary risk factors for knee osteoarthritis:associations of serum vitamin D, metabolic syndrome, dietary magnesium intake and serum C-reactive protein with the risk of knee osteoarthritis

Abstract The knee joint is the most usual site of osteoarthritis (OA). Knee OA is a leading cause of knee pain and loss of function, especially among older age groups. In Finland, in the Health 2000 Survey, 6% of men and 8% of women had prevalent knee OA. The disease’s course is chronic and progressive, and no curative treatment options are currently known. The basis of the treatment consists of conservative methods including weight loss, physical therapy, pain medication and other methods that relieve symptoms and improve functional ability. Surgical interventions, most commonly total joint replacement, are considered when conservative methods prove inadequate. Knee OA has shown to have several load-based risk factors, such as overweight, work-related loading factors and knee malalignment. Of the systemic knee OA risk factors, most evidence exists on female gender and genetic factors. There is growing interest in the potential systemic risk factors of knee OA, such as low serum vitamin D levels, metabolic syndrome and its components, low-grade systemic inflammatory state, and low dietary magnesium intake. Many aspects in the results of previous studies have been conflicting. The objective of the present study was to examine the potential systemic risk factors of knee OA. For this prospective cohort study, patient data were obtained from the nationally representative Mini-Finland Health survey and Health 2000 survey databases. Follow-up data on incident knee OA cases were obtained from the national Care Register for Health Care database. In the present study, none of the studied potential risk factors for knee OA — low serum 25-hydroxyvitamin D, metabolic syndrome or its individual components, serum high sensitivity C-reactive protein or lower dietary magnesium intake — were associated with an increased risk of developing knee OA. Instead, elevated fasting plasma glucose levels decreased the risk of incident knee OA. We also found that serum 25-hydroxyvitamin D seemed to predict the risk of knee OA indirectly during the season with more sunlight and directly during the season with less sunlight, but this association was probably not causal.Tiivistelmä Polvi on yleisin nivelrikon kohdenivel. Polven nivelrikko on yleinen polvikivun sekä toiminnanvajauksen syy etenkin iäkkäämmässä väestössä. Suomessa polven nivelrikkoa sairasti Terveys 2000 -terveystutkimuksen aineistossa noin 6 % miehistä ja 8 % naisista. Taudinkulku on krooninen ja etenevä. Polven nivelrikolle ei tunneta parantavaa hoitoa, ja hoidon peruspilarit ovatkin painon pudotus, omaehtoinen kuntoutus, kipulääkitys sekä muut konservatiiviset, oireita lievittävät ja toimintakykyä parantavat hoitomuodot. Konservatiivisen hoidon osoittautuessa riittämättömäksi, harkitaan kirurgisia hoitomuotoja, joista yleisin on polven tekonivelleikkaus. Polven nivelrikolle tunnetaan useita kuormituksellisia riskitekijöitä, kuten ylipaino ja työhön liittyvät kuormitustekijät sekä polven virheasennot. Systeemisistä polven nivelrikon riskitekijöistä eniten tieteellistä näyttöä on naissukupuolesta ja geneettisistä tekijöistä. Mielenkiinto mahdollisia polven nivelrikon systeemisiä riskitekijöitä, kuten seerumin alhaista D-vitamiinitasoa, metabolista oireyhtymää ja sen komponentteja, elimistön matala-asteista tulehdustilannetta sekä vähäistä magnesiumin saantia kohtaan on kasvussa, mutta aiempien tutkimusten tulokset ovat monelta osin ristiriitaisia. Tämän tutkimuksen tavoite oli tutkia polven nivelrikon potentiaalisia koko elimistön kautta vaikuttavia eli systeemisiä riskitekijöitä. Prospektiivisessa kohorttitutkimuksessa käytettiin aineistoina kansallisesti edustavia Mini-Suomi - ja Terveys 2000 -terveystutkimusten aineistoja sekä Terveyden ja hyvinvoinnin laitoksen hoitoilmoitusrekisteristä poimittuja polven nivelrikkoa sairastavia potilaita. Osatutkimuksissa ei todettu minkään tutkituista mahdollisista riskitekijöistä — matalien seerumin D-vitamiinitasojen, metabolisen oireyhtymän tai sen komponenttien, seerumin herkän C-reaktiivisen proteiinin tai ravinnon matalamman magnesiumin saannin tilastollisesti merkitsevästi lisäävän polven nivelrikon ilmaantumisen riskiä. Sen sijaan, kohonneen paastosokerin todettiin merkitsevästi vähentävän polven nivelrikon riskiä. Seerumin D-vitamiinipitoisuus vaikutti ennustavan polven nivelrikon riskiä käänteisesti valoisana vuodenaikana ja suoraan vähäisemmän auringonvalon aikaan, mutta tämä yhteys ei luultavasti ole kausaalinen

Associations of Metabolic Syndrome and Its Components with the Risk of Incident Knee Osteoarthritis Leading to Hospitalization: A 32-Year Follow-up Study

First Published December 21, 201

Associations of metabolic syndrome and its components with the risk of incident knee osteoarthritis leading to hospitalization:a 32-year follow-up study

Abstract Objectives: To examine whether metabolic syndrome or its individual components predict the risk of incident knee osteoarthritis (OA) in a prospective cohort study during a 32-year follow-up period. Design: The cohort consisted of 6274 participants of the Mini-Finland Health Survey, who were free from knee OA and insulin-treated diabetes at baseline. Information on the baseline characteristics, including metabolic syndrome components, hypertension, elevated fasting glucose, elevated triglycerides, reduced high-density lipoprotein, and central obesity were collected during a health examination. We drew information on the incidence of clinical knee OA from the national Care Register for Health Care. Of the participants, 459 developed incident knee OA. In our full model, age, gender, body mass index, history of physical workload, smoking history, knee complaint, and previous injury of the knee were entered as potential confounding factors. Results: Having metabolic syndrome at baseline was not associated with an increased risk of incident knee OA. In the full model, the hazard ratio for incident knee OA for those with metabolic syndrome was 0.76 (95% confidence interval [0.56, 1.01]). The number of metabolic syndrome components or any individual component did not predict an increased risk of knee OA. Of the components, elevated plasma fasting glucose was associated with a reduced risk of incident knee OA (hazard ratio 0.71, 95% confidence interval [0.55, 0.91]). Conclusions: Our findings do not support the hypothesis that metabolic syndrome or its components increase the risk of incident knee OA. In fact, elevated fasting glucose levels seemed to predict a reduced risk