Hypothyroidism and Mortality among Dialysis Patients

[helvella]

If you are unfortunate enough to be struck by kidney disease and be on dialysis this should be of interest.

As I read it, it is saying that those on dialysis, are hypothyroid and are not adequately treated with thyroid hormone have a significantly higher mortality. Those adequately treated do not.

If this is you, it might be a good idea to pass this information on to your doctors.

1. Clin J Am Soc Nephrol. 2012 Dec 20. [Epub ahead of print]

Hypothyroidism and Mortality among Dialysis Patients.

Rhee CM, Alexander EK, Bhan I, Brunelli SM.

Renal Division, Division of Endocrinology, Diabetes, and Hypertension, and Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts;, ‡Harvard Medical School, Boston, Massachusetts, §Renal Division, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts.

Abstract

BACKGROUND AND OBJECTIVES:

Hypothyroidism is highly prevalent among ESRD patients, but its clinical significance and the benefits of thyroid hormone replacement in this context remain unclear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS:

This study examined the association between hypothyroidism and all-cause mortality among 2715 adult dialysis patients with baseline thyrotropin levels measured between April of 2005 and April of 2011. Mortality was ascertained from Social Security Death Master Index and local registration systems. The association between hypothyroidism (thyrotropin greater than assay upper limit normal) and mortality was estimated using Cox proportional hazards models. To reduce the risk of observing reverse-causal associations, models included a 30-day lag between thyrotropin measurement and at-risk time.

RESULTS:

Among 350 (12.9%) hypothyroid and 2365 (87.1%) euthyroid (assay within referent range) patients, 917 deaths were observed during 5352 patient-years of at-risk time. Hypothyroidism was associated with higher mortality. Compared with thyrotropin in the low-normal range (0.4-2.9 mIU/L), subclinical hypothyroidism (thyrotropin >upper limit normal and =10.0 mIU/L) was associated with higher mortality; high-normal thyrotropin (=3.0 mIU/L and =upper limit normal) and overt hypothyroidism (thyrotropin >10.0 mIU/L) were associated with numerically greater risk, but estimates were not statistically significant. Compared with spontaneously euthyroid controls, patients who were euthyroid while on exogenous thyroid replacement were not at higher mortality risk, whereas patients who were hypothyroid were at higher mortality risk. Sensitivity analyses indicated that effects on cardiovascular risk factors may mediate the observed association between hypothyroidism and death.

CONCLUSIONS:

These data suggest that hypothyroidism is associated with higher mortality in dialysis patients, which may be ameliorated by thyroid hormone replacement therapy.

PMID: 23258793

ncbi.nlm.nih.gov/pubmed/232...

Rod

[nostoneunturned]

Thanks, Rod, very interesting. Sounds like the perfect and terrible way of reducing a sick fraction of the population by undetectable means - or have I completely misunderstood this? Is this why a TSH of 10 is required (disgracefully)before a person is reckoned to have overt hypothyroidism, I think on both sides of the Atlantic now, if I remember Mary Shomon correctly.

[helvella Administrator Thyroid UK in reply to nostoneunturned]

One of the problems is that this is supposed to apply to the strictly sub-clinical hypothyroidism - that is, those with NO symptoms. As soon as people present with symptoms, the guidelines are different. Unfortunately, few of the doctors making the decisions seem to appreciate that!

(At least, that is the way I see them. I could well be wrong.)

[nostoneunturned in reply to helvella]

The problem I have with the import of this report is that there will be many currently receiving dialysis who, unknown to them, have subclinical hypothyroidism with "associated with higher mortality" or even have overt hypthyroidism, as both conditions often are not recognised and diagnosed by doctors.

I speak as one (of many) completely ignored, and told thyroid was "working" for years, that presenting a list of symptoms (rebuffed, unread) meant I was a hypochondriac, my concerns about my puffy gargoyle like face were those of a "silly, vain woman" while I crumbled and finally fell apart in style, then was grossly undertreated for a couple of years until Dr Toft was involved.

I wonder just how many with similar stories have to be on dialysis and make thier final exit.

[shaws Administrator]

This is what Dr Lowe said re treatment and 'replacement' means keeping TSH within range:-

Increased Incidence of Disease and Medication Use Among Patients on T4-replacement

Researchers recently conducted the first large, community-based study in the UK of the health status of hypothyroid patients using T4-replacement therapy.[37] Compared to matched control patients, hypothyroid patients on "adequate" dosages of T4 had a higher reported incidence of four diseases: depression, hypertension, diabetes, and heart disease. Hypothyroid patients on inadequate T4-replacement (their TSH levels were elevated) also had a higher incidence of strokes. In addition, hypothyroid patients chronically used more prescription drugs, especially for diabetes, cardiovascular disease, and gastrointestinal conditions.

We’ve recently been consulted by many hypothyroid patients whose physicians have reduced their T4 dosages to extremely low amounts, in some cases as low as 25 mcg. The patients report to us that their physicians refer to reports by endocrinologists that TSH suppression increases the risk of atrial fibrillation three-fold. As I explain in Addendum 4, this is an unjustified generalization from a study of elderly (60 years of age and older) sedentary people. This misguided practice by physicians is likely to increase the patients’ incidence of coronary artery disease and cardiac fatalities.

The dosage of T4 that suppresses the TSH level varies considerably, but may be as much as 171 mcg or as little as 50 mcg.[56][57][58][59][60][61][62] Hypothyroid patients should be concerned when their physicians restrict them to lower-end dosages of T4. In one study, researchers used coronary angiography to assess the progression of coronary atherosclerosis in elderly hypothyroid patients. In 5 of 6 patients who kept their T4 dosages at 150 mcg or more, the disease didn’t progress. But in all 6 patients whose dosages were 100 mcg or less, the disease had progressed.[63] This study suggests that elderly patients whose TSH levels are suppressed by fairly low dosages of T4, and whose physicians insist on keeping their TSH levels within the reference range, may, as a result, have increased progression of coronary artery disease, leading to strokes and/or heart attacks. In that the incidence of atherosclerosis is high even among young individuals in modern societies, younger hypothyroid patients should be concerned over the possibility of lower dosages of thyroid hormone inducing or exacerbating atherosclerosis.

web.archive.org/web/2010103... Suffering of Many Patients on T4-replacement