Reversal of nocturnal non-dipping of blood pressure after Levothyroxine therapy in patients with subclinical hypothyroidism.

AIMS

To study the loss of diurnal variation in blood pressure in normotensive patients with Subclinical/overt hypothyroidism and effect of Levothyroxine (L-T4) treatment.

MATERIALS AND METHODS

In this interventional study Eighty patients between 17- 50 years with newly detected OH and SCH (74 women and 6 men) and nine euthyroid subjects (all men) with blood pressure <140/90 were recruited. All patients underwent 24h ambulatory blood pressure monitoring (ABPM) using ABPM machine before and after treatment with L-T4. Diurnal index (DI), Percent time elevation (PTE), Hyperbaric impact (HBI) were studied pre and post L-T4 treatment.

RESULTS

Of the 89 subjects (22 SCH, 58 OH and 9 controls), 7 of the SCH and 30 of OH subjects reported back in follow up after L-T4 supplementation for evaluation. DI, HBI and PTE when compared at baseline between different groups (SCH- OH, SCH- control, OH- control) were insignificant. After L-T4 supplementation DI, HBI and PTE varied significantly with p value 0.007, 0.003 and 0.003 respectively between SCH- OH only. Post L-T4 analysis in SCH group was statistically insignificant (p-value 0.102) but a trend toward improvement in DI was noted (baseline and post treatment DI mean 7.00 and 13.00 respectively).

CONCLUSION

Loss of nocturnal dipping was found in patients with OH and SCH which was restored after L-T4 therapy only in patients with SCH and not with OH.

TREATMENT

of SCH patients with high cardiovascular risk may be beneficial in this setting and can be a new indication for LT4 therapy in SCH.