Very low-calorie ketogenic diet (VLCKD): an antihypertensive nutritional approach

Abstract

Background: Obesity is accompanied by hormonal, inflammatory and endothelial alterations. These alterations induce a stimulation of several other mechanisms that contribute to the hypertensive state and to increase the cardiovascular morbidity. This pilot, open - label, single- center, prospective clinical trial aimed to evaluate the effect of very low- calorie ketogenic diet (VLCKD) on blood pressure (BP) in women with of obesity and hypertension.

Methods: A total of 137 women, who met the inclusion criteria and accepted to adhere to VLCKD, were consecutively enrolled. Assessment of anthropometric parameters (weight, height, and waist circumference), body composition (through bioelectrical impedance analysis), systolic (SBP) and diastolic blood pressure (DBP) and blood sample collection were carried out at baseline and after 45 days of the active phase of VLCKD.

Results: After VLCKD all the women experienced a significant reduction in body weight and an overall improvement of body composition parameters. In addition, high sensitivity C reactive protein (hs- CRP) levels were significantly diminished (p < 0.001), while phase angle (PhA) increased by almost 9% (p < 0.001). Interestingly, both SBP and DBP were significantly improved (-12.89% and - 10.77%, respectively; p < 0.001). At baseline, SBP and DBP showed statistically significant correlations with body mass index (BMI), waist circumference, hs-CRP levels, PhA, total body water (TBW), extracellular water (ECW), Na / K ratio, and fat mass. Even after VLCKD, all correlations among SBP and DBP with the study variables were statistically significant, except for the association between DBP and Na / K ratio. Changes (%) in both SBP and DBP were associated with ∆BMI%, ∆PhA% and ∆hs- CRP levels (p < 0.001). In addition, only ∆SBP% was associated with ∆waist circumference (p = 0.017), ∆TBW (p = 0.017), and ∆fat mass (p < 0.001); while only ∆DBP% was associated with ∆ECW (p = 0.018), and ∆Na / K ratio (p = 0.048). After adjusting for ∆BMI, ∆WC, ∆PhA, ∆TBW, and ∆fat mass, the correlation between changes in ∆SBP and ∆hs -CRP levels remained statistically significant (p < 0.001). Similarly, the correlation between ∆DBP and ∆hs- CRP levels also remained statistically significant after adjustment for ∆BMI, ∆PhA, ∆Na / K ratio, and ∆ECW (p < 0.001). From multiple regression analysis ∆hs- CRP levels seemed to be the main predictor of changes of BP (p < 0.001).

Conclusion: VLCKD reduces BP in women with of obesity and hypertension in a safely manner.

Keywords: Blood pressure; Fat mass; Hypertension; Inflammation; Obesity; VLCKD; Very low-calorie ketogenic diet.

Fig. 1

Timeline of assessment

Fig. 2

The change in blood pressure during the 45 days of VLCKD (active phase). After VLCKD, both SBP and DBP parameters were significantly decreased (p < 0.001). VLCKD very low- calorie ketogenic diet, SBP systolic blood pressure, DBP diastolic blood pressure

Fig. 3

Correlation between changes in ∆SBP and ∆hs - CRP levels after adjusting for ∆BMI, ∆WC, ∆PhA, ∆TBW, and ∆FM. A p value in bold type denotes a significant difference (p < 0.05). SBP systolic blood pressure, hs -CRP high -sensitivity C-reactive protein

Fig. 4

Correlation between changes in ∆DBP and ∆hs - CRP levels after adjusting for ∆BMI, ∆PhA, ∆Na / K ratio, and ∆ECW. A p value in bold type denotes a significant difference (p < 0.05). DBP diastolic blood pressure, hs-CRP high-sensitivity C-reactive protein

Fig. 5

Very low-calorie ketogenic Diet mechanisms underlying blood pressure reduction