Subclinical hypothyroidism in combination with vitamin D deficiency increases the risk of impaired left ventricular diastolic function

Endocr Regul. 2015 Apr;49(2):84-90. doi: 10.4149/endo_2015_02_84.

Abstract

Objective: Subclinical hypothyroidism and vitamin D deficiency are common. The diastolic function of patients with both subclinical hypothyroidism and vitamin D deficiency remains unknown. This study aimed to investigate diastolic dysfunction in patients with both subclinical hypothyroidism and vitamin D deficiency.

Subjects and methods: This study included 254 patients. All patients underwent standard Doppler echocardiography. Patients who had risk factors for diastolic dysfunction or had used L-thyroxine and vitamin D within the previous 3 months were excluded. Vitamin D deficiency was defined as a 25-OH-vitamin D level lower than 20 ng/ml, and vitamin D sufficiency was defined as a 25-OH-vitamin D level ≥ 30 ng/ml. Subclinical hypothyroidism was defined as a TSH level of 4.5-10 mU/l when the free T4 concentration was normal.

Results: The patients were divided into 4 groups. Group 1 (n=71) included patients with subclinical hypothyroidism and vitamin D deficiency; Group 2 (n=66) included patients with subclinical hypothyroidism and vitamin D sufficiency; Group 3 (n=65) included euthyroid patients with vitamin D deficiency; and Group 4 (n=52) included euthyroid patients with vitamin D sufficiency. LAVI (31.3 ± 3.2, 28.7 ± 3.0, 28.4 ± 3.4, and 27.9 ± 3.9; p<0.001) and E/E' values (11.2 ± 2.7, 8.9 ± 2.7, 9.1 ± 2.9, 8.8 ± 2.5; p<0.001) were significantly higher in Group 1 than in Groups 2, 3 and 4. E' values were significantly lower in Group 1 than in Groups 2, 3 and 4.

Conclusion: The coexistence of subclinical hypothyroidism with vitamin D deficiency can lead to further deterioration in the LV diastolic function via the regulation of intracellular calcium and induction of inflammatory activity. Therefore, close follow-up of the diastolic functions of these patients could be beneficial.

Keywords: diastolic function; echocardiography.; subclinical hypothyroidism; vitamin D deficiency.

MeSH terms

  • Adult
  • Asymptomatic Diseases
  • Cohort Studies
  • Cross-Sectional Studies
  • Echocardiography, Doppler
  • Female
  • Humans
  • Hypothyroidism / complications
  • Hypothyroidism / diagnostic imaging
  • Hypothyroidism / epidemiology*
  • Male
  • Middle Aged
  • Risk Factors
  • Ventricular Dysfunction, Left / diagnostic imaging
  • Ventricular Dysfunction, Left / epidemiology*
  • Ventricular Function, Left
  • Vitamin D Deficiency / complications
  • Vitamin D Deficiency / diagnostic imaging
  • Vitamin D Deficiency / epidemiology*