Osteocalcin

On May 10, 2010, in Minerals, Tests, by Andrea

Osteocalcin is one of those strange labs that we recommend that no one seems to know what it is — including, I think, some of the docs that may or may not actually order it.

Because it is one of the more obscure labs, many docs will not actually run it for you, but let’s go over it to explain what it is, why it’s important, and why it’s gaining ground in the lab-work field.

Remember that ranges are just that — ranges.  Nothing is set in stone, and each lab sets their own range.  Your mileage may vary.

This is a fasting test.

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Scripted D Fail.

On March 22, 2010, in Fat Solubles, Vitamins, by Andrea

Going back to my roots a bit and explain a common problem in the WLS community — scripted vitamin D supplements.

Drisdol

Drisdol is the trade name for the prescription strength vitamin D treatment.  It is 50,000 IU of D2, suspended in an oil-base.  The typical regimen is 1 per week for 8 or 12 weeks, then retest.  This is in additional to the vitamin D that is packaged in calcium supplements and possibly additional vitamin D taken through the week depending on the prescriber.

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Diabetes drugs increase fracture risk

On January 22, 2010, in Uncategorized, by Andrea

Hopefully, most of y’all are off diabetes meds, but just in case –

These drugs are those like Avandia and Actos.

From Medscape:

Thiazolidinediones up Risk of Fractures in Older Women

NEW YORK (Reuters Health) Jan 21 – Thiazolidinediones (TZDs) are linked to an increased risk for extremity fractures in women over age 65, findings from a large retrospective cohort study indicate.

Mainly used in diabetics, TZDs are agonists of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma), a nuclear transcription factor. PPAR-gamma is expressed in fat cells, where activation by TZDs improves insulin sensitivity.

But PPAR-gamma is also expressed in osteoblasts, osteoclasts, and bone marrow stromal cells, where activation by TZDs can contribute to bone loss, according to a report of the study in the February Journal of Clinical Endocrinology and Metabolism.

“Given the prevalent use of TZDs in patients with diabetes and that this patient population is already at risk for fractures, it is important to assess the effect of these drugs on fracture risk,” senior author Dr. L. Keoki Williams and her associates write.

The researchers, from Henry Ford Hospital in Detroit, studied claims data and medical records for 19,070 diabetic patients (50% female; mean age 58 years) enrolled at a health maintenance organization between 2000 and 2007. All the patients used oral diabetes medication, and 4511 had filled at least one prescription for a TZD (rosiglitazone and/or pioglitazone).

Ninety-five patients in the TZD group and 382 not treated with a TZD developed a fracture. The unadjusted first event rates were 7.0 and 5.3 per 1000 patient-years. At about a year and a half, the Kaplan-Meier curves began to separate and remained separated for the rest of the study period.

TZD use was associated with an adjusted hazard ratio of 1.34 in analyses controlling for sociodemographics, other medication use, HbA1c levels, and comorbidities.

However, after stratification by age and sex, only women over age 65 were at significantly elevated risk for fracture with TZD use (aHR 1.72). The increased risk was not apparent until after a year of TZD therapy, the researchers note.

A post hoc analysis indicated that TZD use affected fractures of the upper extremity and distal lower extremity, but not fractures of the femur and vertebrae.

Although theirs is one of the largest cohort studies to examine the longitudinal relationship between TZD use and fractures, the investigators note that their analyses did not take into account other important risk factors, including body mass index, smoking, nephropathy, and bone mineral density.

Given that older women are already at risk for fractures, the new findings complicate decisions for when and how to screen for bone density deficits in patients who’ve been taking these drugs.

“For example,” the authors caution, “the increase in bone marrow fat caused by TZDs may result in underestimating dual-energy x-ray absorptiometry-measured bone mineral density.”

J Clin Endocrinol Metab 2010.

Calcium+D may reduce fracture risk

On January 22, 2010, in Fat Solubles, Minerals, Vitamins, by Andrea

Um.  Duh?

But for the 2 of you that have not been paying attention.

Take your calcium (citrate) and D.

From Medscape:

Daily Calcium Plus Vitamin D Supplements May Reduce Fracture Risk

Laurie Barclay, MD

January 22, 2010 — Daily supplements of calcium plus vitamin D, but not of vitamin D alone, are associated with significantly reduced fracture risk, according to the results of a patient level-pooled analysis reported in the January 12 issue of the BMJ.

“A large randomised controlled trial in women in French nursing homes or apartments for older people showed that calcium and vitamin D supplementation increased serum 25-hydroxyvitamin D, decreased parathyroid hormone, improved bone density, and decreased hip fractures and other non-vertebral fractures,” write B. Abrahamsen, from Copenhagen University Hospital Gentofte, in Copenhagen, Denmark, and colleagues from the DIPART (vitamin D Individual Patient Analysis of Randomized Trials) Group.

“Subsequent randomised trials examining the effect of vitamin D supplementation — with or without calcium — on the incidence of fractures have produced conflicting results….We used individual patient data methods to do a meta-analysis of randomised controlled trials of vitamin D — with or without calcium — in preventing fractures and investigated if treatment effects are influenced by patients’ characteristics.”

The goals of the study were to identify characteristics affecting the antifracture efficacy of vitamin D or vitamin D plus calcium regarding any fracture, hip fracture, and clinical vertebral fracture and to evaluate the effects of dosing regimens and coadministration of calcium.

Selection criteria were randomized trials with at least 1 intervention group in which vitamin D was given, in which there were at least 1000 participants, and in which fracture was an outcome. The investigators identified 7 major randomized trials of supplementation with vitamin D plus calcium or with vitamin D alone, enrolling a total of 68,517 participants. Mean age was 69.9 years (range, 47 – 107 years), and 14.7% of participants were men. Significant interaction terms were identified with logistic regression analysis, followed by Cox’s proportional hazards models incorporating age, sex, fracture history, and use of hormone therapy and bisphosphonates.

Overall risk for fracture was decreased in trials using vitamin D with calcium (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.86 – 0.99; P = .025), and risk for hip fracture was also decreased (HR for all studies, 0.84; 95% CI, 0.70 – 1.01; P = .07; HR for studies using 10 μg of vitamin D given with calcium, 0.74; 95% CI, 0.60 – 0.91; P = .005). There were no significant effects for vitamin D alone in daily doses of 10 μg or 20 μg, nor was there any apparent interaction between fracture history and treatment response. No interaction was noted for age, sex, or use of hormone replacement therapy.

“This individual patient data analysis indicates that vitamin D given alone in doses of 10-20 μg is not effective in preventing fractures,” the study authors write. “By contrast, calcium and vitamin D given together reduce hip fractures and total fractures, and probably vertebral fractures, irrespective of age, sex, or previous fractures.”

Limitations of this study include lack of data for 4 of the 11 identified studies meeting inclusion criteria, and insufficient information about compliance to do a per protocol analysis. In addition, only a single study provided data for vitamin D given alone at the lower dose.

“We must emphasise that this analysis does not allow for a direct comparison of vitamin D against vitamin D given with calcium, but only comparisons between each intervention and no treatment,” the study authors conclude. “Whether intermittent doses of vitamin D given without calcium supplements can reduce the risk of fractures remains unresolved from the studies in this analysis. Additional studies of vitamin D are also needed, especially trials of vitamin D given daily at higher doses without calcium.”

In an accompanying editorial, Dr. Opinder Sahota, from Queen’s Medical Centre in Nottingham, United Kingdom, notes that these findings are important because they show that vitamin D alone, irrespective of dose, does not reduce the risk for fracture.

“Although the evidence is still confusing, there is growing consensus that combined calcium and vitamin D is more effective than vitamin D alone in reducing non-vertebral fractures,” Dr. Sahota writes. “Higher doses are probably necessary in people who are more deficient in vitamin D, and treatment is probably more effective in those who maintain long term compliance. Further studies are needed to define the optimal dose, duration, route of administration, and dose of the calcium combination.”

The National Heart, Lung, and Blood Institute, National Institutes of Health, supported this study. Some of the study authors have disclosed various financial relationships with Novartis, Amgen, Nycomed, Eli Lilly, Procter & Gamble, Merck, Roche, Shire, ProStrakan, Servier, Celltech, ProStrakan, Alliance for Better Bone Health, GlaxoSmithKline, Pfizer, Sanofi-Aventis, and/or Osteologix.

Dr. Sahota has disclosed no relevant financial relationships.

BMJ. 2010;340:b5463.

Osteoporosis Basics

On January 14, 2010, in Minerals, by Andrea

Good, basic info.

From CNN.com:

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