2 Matching Annotations
  1. Jan 2020
    1. RESULTS: In the hypothyroid state, the plasma volume measured by dilution of 125I-albumin (APV) was higher than the calculated plasma volume (CPV) from packed red cell mass, suggesting an extravascular escape of albumin. After substitutive therapy, the CPV showed a statistical increase (P < 0.05), whereas APV remained unchanged. Both ERPF and GFR increased after thyroxine therapy (p < 0.05). In the subclinical group, blood volumes and renal function were similar to those found in the other group of patients when in the euthyroid state.

      If this holds true, I'd expect rapid blood volume expansion from thyroid hormone. I'm also interested in whether thyroid hormone stimulates the production of albumin, given its anabolic properties.

    1. Thyrotoxicosis creates a hyperdynamic circulatory state because of a marked fall in peripheral vascular resistance and associated increase in venous return, increased total blood volume, increased cardiac contractility and heart rate.

      If the mechanism is really the same as alpha blockers, then the blood volume expansion may be expected to be similar in constitution. However, I would expect more red blood cells in thyroid mediated volume expansion compared to alpha blockers. The reason, obviously, is because of the increased oxygen demand from thyroid hormone.