Bone Turnover Marker Profiling and Fracture Risk in Older Women: Fracture Risk from Age 75 to 90.

Purpose: A major challenge in osteoporosis is to identify individuals at high fracture risk. We investigated six bone turnover markers (BTMs) to determine association with specific fracture types; the time-frame for risk prediction and whether these are influenced by age at assessment.Methods: Population-based OPRA cohort (n = 1044) was assessed at ages 75, 80, 85 and fractures documented for up to 15 years. Six BTMs were analyzed at each time-point (N-terminal propeptide of type I collagen, PINP; total osteocalcin, OC; bone-specific alkaline phosphatase, BALP; C-terminal telopeptide of type I collagen, CTX; tartrate-resistant acid phosphatase 5b, TRAcP5b; urinary osteocalcin). Hazard ratios (HR) for any, major osteoporotic, vertebral and hip fractures were calculated as short (1, 2, 3 years) and long-term risk (5, 10, 15 years).Results: At 75 year, high CTX levels were associated with an increased risk of all fractures, including major osteoporotic fractures, across most time-frames (HRs ranging: 1.28 to 2.28). PINP was not consistently associated. Urinary osteocalcin was consistently associated with elevated short-term risk (HRs ranging: 1.83-2.72). Other BTMs were directionally in accordance, though not all statistically significant. BTMs were not predictive for hip fractures. Association of all BTMs attenuated over time; at 80 year none were associated with an increased fracture risk.Conclusion: CTX, urinary OC and TRAcP5b are predictive for fracture in a 1 to 3 year, perspective, whereas in the long-term or above age 80 years, BTMs appear less valuable. Resorption markers, particularly CTX, were more consistently associated with fracture risk than formation markers in the very elderly.</p

The complexity of kidney disease and diagnosing it – cystatin C, selective glomerular hypofiltration syndromes and proteome regulation

Estimation of kidney function is often part of daily clinical practice, mostly done by using the endogenous glomerular filtration rate (GFR)-markers creatinine or cystatin C. A recommendation to use both markers in parallel in 2010 has resulted in new knowledge concerning the pathophysiology of kidney disorders by the identification of a new set of kidney disorders, selective glomerular hypofiltration syndromes. These syndromes, connected to strong increases in mortality and morbidity, are characterized by a selective reduction in the glomerular filtration of 5–30 kDa molecules, such as cystatin C, compared to the filtration of small molecules <1 kDa dominating the glomerular filtrate, for example water, urea and creatinine. At least two types of such disorders, shrunken or elongated pore syndrome, are possible according to the pore model for glomerular filtration. Selective glomerular hypofiltration syndromes are prevalent in investigated populations, and patients with these syndromes often display normal measured GFR or creatinine-based GFR-estimates. The syndromes are characterized by proteomic changes promoting the development of atherosclerosis, indicating antibodies and specific receptor-blocking substances as possible new treatment modalities. Presently, the KDIGO guidelines for diagnosing kidney disorders do not recommend cystatin C as a general marker of kidney function and will therefore not allow the identification of a considerable number of patients with selective glomerular hypofiltration syndromes. Furthermore, as cystatin C is uninfluenced by muscle mass, diet or variations in tubular secretion and cystatin C-based GFR-estimation equations do not require controversial race or sex terms, it is obvious that cystatin C should be a part of future KDIGO guidelines.publishedVersio

Kidney Function During Ageing and its Association with Bone Mass, Fracture and Mortality

Osteoporosis and osteoporosis related fractures are a major health care challenge both in Sweden and globally. The cost and suffering from osteoporosis are expected to increase since the population of elderly is increasing. Bone health can be affected by altered mineral homeostasis, which in its turn can be affected by reduced kidney function. However, the course of age-related decline in kidney function and its association to osteoporosis andfracture in the very elderly need further investigation since longitudinal data are scarce. Therefore, this thesis has two main aims; 1) to investigate kidney function during ageing and 2) its association to bone health in a cohort ofelderly women.Data was collected through the Malmö Osteoporosis Prospective Risk Assessment (OPRA) cohort, a prospective cohort of 1044 community dwelling women, all aged 75 and followed for ten years with reinvestigations at age 80and 85. Data on BMD, fracture and blood biochemistry was available at all three time points.Estimated kidney function greatly depends on which marker and study equation is used. The discrepancies are to such an extent that could affect whether a person is diagnosed with chronic kidney disease (CKD) or not, of particular importance in the elderly. Only women with the worst kidney function, corresponding to CKD stage 3b-5, had continuously increased mortality risk. This indicates that an age-dependent CKD definition would be of valuein elderly women.Kidney function in elderly women was associated with markers of mineral homeostasis, bone loss and BMD, but the effect size was relatively small compared to other risk factors. Also, fracture risk was increased only in womenwith mild-moderate reduction of kidney function (CKD stage 3a) and not in women with the worst kidney function (CKD stage 3b-5). Low BMD was associated with increased fracture risk independent of kidney function. Havingboth reduced kidney function and osteoporosis could present an additional risk increase.In conclusion, estimated kidney function in elderly women greatly depends on method of estimation and the results advocate for an age-adapted CKD definition. Maintaining adequate kidney function is important formaintaining bone health, although in old age it is probable that the effect size of any single specific risk factor is smaller compared with younger individuals

Muscle mass, creatinine, cystatin C, and selective glomerular hypofiltration syndromes

In this issue of Clinical Kidney Journal, Stehlé and colleagues demonstrate that estimation of glomerular filtration rate (GFR) by use of creatinine and a measure, total lumbar muscle cross-sectional area, reflecting the total muscle mass of an individual, is superior to GFRestimating equations based upon creatinine and demographic variables. The report by Stehlé et al demonstrates one solution to the interference of muscle mass in the use of creatinine to estimate GFR. This interference was identified already at the start in 1959 of using creatinine for estimation of GFR. Different ways of taking the muscle mass into account when creatinine-based estimations of GFR have been used generally include use of controversial race and sex coefficients. A new marker of GFR, cystatin C, introduced in 1979, has been shown to be virtually uninfluenced by muscle mass. In this editorial, the simultaneous use of creatinine and cystatin C to estimate GFR, muscle mass and selective glomerular hypofiltration syndromes is described

Can frailty in conjunction with FRAX identify additional women at risk of fracture - a longitudinal cohort study of community dwelling older women

Background: Fracture risk assessment is still far from perfect within the geriatric population. The overall aim of this study is to better identify older women at risk for fractures, using a quantitative measure of frailty in conjunction with the web-based Fracture Risk Assessment Tool (FRAX®). Methods: This study was performed in the Osteoporosis Risk Assessment (OPRA) cohort of n = 1023, 75-year-old women followed for 10-years. A frailty index (FI) of ‘deficits in health’ was created, and FRAX 10-year probability for major osteoporotic and hip fractures was calculated and bone mineral density measured. Incident fractures were continuously registered for 10-years. Receiver Operating Characteristic (ROC) curves were used to compare FI, FRAX and the combination FI + FRAX as instruments for risk prediction. Discriminative ability was estimated by comparing Area Under the Curve (AUC). In addition, using guidelines from the Swedish Osteoporosis Foundation, a category of low risk women who would not have been recommended for pharmacological treatment (non-treatment group) was identified, categorized by frailty status and for relative risk analysis, hazard ratios (HR) and 95% confidence intervals were calculated using Cox proportional hazard regressions. Results: For hip fracture, FRAX and frailty performed almost equally (HIP AUC 10y: 0.566 vs. 0.567, p = 0.015 and p = 0.013). Next, FI was used in conjunction with FRAX; proving marginally better than either score alone (AUC 10y: 0.584, p = 0.002). Comparable results were observed for osteoporotic fracture. In the non-treatment group (564 women), being frail was associated with higher 10y hip fracture risk (HR 2.01 (1.13–3.57)), although failing to reach statistical significance for osteoporotic fracture (HR 1.40 (0.97–2.01). The utility of measuring frailty was also demonstrated when using T-score as an index of bone density to define fracture risk. Among n = 678 non-osteoporotic women, frailty added to the 10-year fracture risk (Hip; HR 2.22 (1.35–3.71); Osteoporotic fracture; HR 1.57 (1.15–2.14)). Conclusions: While the addition of frailty to FRAX marginally improved fracture prediction, applying a frailty measurement to a group of ‘low risk’ women, identified a set of individuals with high actual hip fracture risk that would not be prioritized for pharmacological treatment. Further cost-benefit analysis studies are needed to formally test potential benefit

Bone health as a co-morbidity of chronic kidney disease

Chronic kidney disease and osteoporosis commonly co-exist in aged patients. Chronic kidney disease affects bone health because of its effect on mineral metabolism in the syndrome, Chronic Kidney Disease Mineral and Bone Disorder, resulting in an increased risk of fractures. Hip fracture risk may be as much as four-fold higher in the worst affected. Tools to estimate fracture risk such as FRAX® and measuring bone density can be used in patients with chronic kidney disease; however, bone density may underestimate fracture risk in this population as it does not give information on bone quality. While osteoporosis treatment in patients with chronic kidney disease stage 1–3 does not differ from the general population, in the absence of Chronic Kidney Disease Mineral and Bone Disorder, patients with disease stage 4–5 require special consideration. It is, however, of the utmost importance that these patients receive pharmacological treatment because of their high risk of fractures

How Does the Level Design in The Last of Us Part 2 Use Lighting and Set Dressing to Suggest Whether an Area Is Safe or Dangerous?

This thesis presents a formal comparative analysis of how the level design in The Last of Us Part 2 uses lighting and set dressing to suggest whether an area is safe or dangerous. The study's findings are relevant to developers of action survival games with elements of horror which are story-based and want to create a solid immersive experience with lighting and set dressing. The research gathered data on lighting and set dressing components in eight game levels.The elements analysed regarding lighting were evenly lit, high-key, low-key, red light, and flashlight. The elements analysed regarding set dressing were decals, overgrown vegetation, fungus and dead bodies. The analysis involved a mix of contextual observations as well as a discreet count of certain elements.A comparison was made between the safe and dangerous levels to understand if the game uses consistent visual language in lighting and set dressing to suggest to players whether a level is safe or dangerous

How Does the Level Design in The Last of Us Part 2 Use Lighting and Set Dressing to Suggest Whether an Area Is Safe or Dangerous?

This thesis presents a formal comparative analysis of how the level design in The Last of Us Part 2 uses lighting and set dressing to suggest whether an area is safe or dangerous. The study's findings are relevant to developers of action survival games with elements of horror which are story-based and want to create a solid immersive experience with lighting and set dressing. The research gathered data on lighting and set dressing components in eight game levels.The elements analysed regarding lighting were evenly lit, high-key, low-key, red light, and flashlight. The elements analysed regarding set dressing were decals, overgrown vegetation, fungus and dead bodies. The analysis involved a mix of contextual observations as well as a discreet count of certain elements.A comparison was made between the safe and dangerous levels to understand if the game uses consistent visual language in lighting and set dressing to suggest to players whether a level is safe or dangerous

Longitudinal Changes in Kidney Function Estimated from Cystatin C and Its Association with Mortality in Elderly Women

Background/Aims: Prospective data on age-related changes in kidney function are required, especially since the current Kidney Disease Improving Global Outcomes (KDIGO) definition has been suggested to classify a large number of elderly people with CKD. Objective: This study, a complement to our previous Cr-based study in the same cohort, is aimed at evaluating cystatin C (cysC)-based changes in kidney function during aging in older women and analyzing the association between CKD and mortality through 10 years of follow-up. Methods: cysC was available in 981 women from the Osteoporosis Prospective Risk Assessment (OPRA) cohort, all aged 75 years on entry. Reinvestigations were made after 5 (n = 685) and 10 years (n = 365). Kidney function was estimated (estimated glomerular filtration rate [eGFR]) using Chronic Kidney Disease Epidemiology Collaboration cysC and Caucasian, Asian, Pediatric, and Adult cysC equations and the change in function calculated. Women were staged equivalent to CKD stage 1, 2, 3a, or 3b-5 according to the KDIGO classification. Mortality risk was estimated for 5-year or 10-year follow-up time using Cox proportional hazard analyses (reference category, CKD stages 1 and 2). Results: Mortality risk for women with the worst kidney function (CKD stages 3b-5) increased during both 5-year follow-up times compared to that for women in stages 1 and 2 (age 75-80 years: adjusted Hazard Ratio [HRadj] 3.9, 95% confidence interval [CI] 2.3-6.5; age 80-85 years: HRadj 1.7, 95% CI 1.0-2.7). In contrast, women in stage 3a had increased risk only in the first 5-year follow-up (HRadj 1.7, 95% CI 1.0-3.0, age 75-80 years). Change in kidney function amounted to a loss of 1.9 (±1.4) mL/min/1.73 m2 per year during the 10-year follow-up, and at age 85 years, 4 of every 5 women had an eGFR equivalent to CKD. Conclusion: In the future, an age-adapted definition of CKD, lowering the threshold for CKD in the elderly, may be beneficial to avoid overdiagnosis of CKD

C-reactive protein, bone loss, fracture, and mortality in elderly women: a longitudinal study in the OPRA cohort.

This longitudinal study investigates the association between C-reactive protein (CRP), osteoporosis, fractures, and mortality in 1044 elderly women. CRP was not an indicator for low bone mineral density (BMD), bone loss, or fracture in elderly women; however, women with elevated CRP levels over a prolonged period lost more bone over the 10-year follow-up, although fracture risk was not increased