Assessment of Anthropometric Indices, Salt Intake and Physical Activity in the Aetiology of Prehypertension

High Prevalence of Prehypertension and its Association with Modifiable Risk Factors: Findings of Household STEPS Survey from Urban Puducherry, South India

BACKGROUND

Prehypertension increases the likelihood of hypertension, cardiovascular diseases, and renal failure, and it is amenable to control if it is detected early. The burden of prehypertension prevalent in the community is not much explored. This study aimed to estimate the prevalence and to identify the socio-behavioral and dietary factors related to prehypertension in South India.

METHODS

A community-based cross-sectional study was carried out where data related to socio-demographic status, substance use, dietary patterns, physical activity, and associated comorbidities were assessed using the WHO STEPwise survey tool. Adults aged >=18 years who were not previously diagnosed and treated for hypertension were assessed for prehypertension. Prevalence of prehypertension is reported as percentage with 95% CI. Association was reported as adjusted prevalence ratio obtained through multivariable log binomial regression adjusted for potential confounders.

RESULTS

Among 2399 participants, 2213 underwent screening. Among 2213 adults, 810 (36.6%, 95% CI: 34.6-38.6%) were in the prehypertension range. The adjusted prevalence for prehypertension was 36.2% among males and 37.2% among females, respectively. Being in the age group of 45-54 years aPR-1.36, body mass index (BMI) >23 Kg/m2 aPR-1.25, consumption of more than 6 grams of salt per day aPR-1.15 times were more likely to be associated with prehypertension. The comorbid conditions such as diabetes are less likely to be associated with prehypertension aPR-0.54 (0.41-0.72).

CONCLUSIONS

This community-based surveillance showed 36% of prehypertension among adults which would have been missed if we were to follow the routine cares such as opportunistic and high-risk-based screening. Since prehypertension increases the risk for various end organ failures, there is an impending need to focus on screening and promote healthy lifestyles.

Effects of added salt reduction on central and peripheral blood pressure

BACKGROUND

Although the effects of salt intake reduction on casual blood pressure have been extensively studied in hypertensive individuals, data on reductions of added salt on arterial stiffness in both normotensive and prehypertensive subjects are scarce.

OBJECTIVE

To evaluate the effects of progressive reduction in added salt intake (from 6 grams to 4 grams per day) on peripheral and central blood pressure and arterial stiffness in normotensive, prehypertensive and hypertensive individuals.

METHODS

This was a single-blinded clinical trial with 13 weeks of follow-up. Normotensive (≤ 130/85 mmHg), prehypertensive (≥ 130 e < 139/≥ 85 e < 90 mmHg) and stage 1 hypertensive individuals (< 139/≥ 85 and < 90 mmHg) were assessed. Casual blood pressure measurements and ambulatory blood pressure monitoring were performed using the automated OMRON 705CP device, and central blood pressure was measured using the Sphygmocor®. Twenty-four-hour urinary sodium excretion and the amounts of added salt consumed were measured. Statistically significance level was set at p < 0.05 for all analysis.

RESULTS

A total of 55 participants (18 normotensive, 15 prehypertensive and 22 hypertensive), median age 48 years (IQR:39-54) were studied. The groups were not different in age or sex. No difference was observed in blood pressure or sodium excretion levels before and after the intervention. No significant changes in arterial stiffness parameters were observed.

CONCLUSION

The progressive reduction in added salt intake during a period of 13 weeks did not cause significant reductions in peripheral and central blood pressure. (Arq Bras Cardiol. 2020; 114(3):554-561).

Association between urinary sodium excretion and uric acid, and its interaction on the risk of prehypertension among Chinese young adults

High uric acid (UA) level and high salt intake are reportedly associated with cardiovascular disease. This study investigated the association between UA and urinary sodium excretion, as well as its interaction on the risk of prehypertension. A total of 1869 participants without hypertension were recruited from a previously established cohort in Shaanxi Province, China. The participants were classified as normotensive or prehypertensive on the basis of their blood pressure. Increasing quartiles of sodium excretion were associated with high urinary UA/creatinine levels in prehypertensive participants. Estimated sodium excretion positively correlated with urinary UA/creatinine excretions in the prehypertensive group. In addition, the multivariate-adjusted odds ratios for prehypertension compared with normotension were 1.68 (1.27–2.22) for sodium excretion and 1.71 (1.21–2.42) for serum UA. Increasing sodium excretion and serum UA were associated with higher risk of prehypertension. Compared with the lowest quartiles, the highest sodium excretion and serum UA quartiles entailed 3.48 times greater risk of prehypertension. Sodium excretion is associated with urinary UA excretion in prehypertensive participants. The present study shows that high levels of salt intake and serum UA simultaneously are associated with a higher risk of prehypertension.

Biotechnological production of the angiotensin-converting enzyme inhibitory dipeptide isoleucine-tryptophan

Peptides with angiotensin-converting enzyme (ACE)-inhibitory and antihypertensive effects are suggested as innovative food additives to prevent or treat hypertension. Currently, these substances are isolated from food proteins following nonselective hydrolysis as a mixture of ACE-inhibitory peptides and other protein fragments. This study presents an innovative biotechnological method, based on recombinant DNA technology that was established to specifically produce the ACE-inhibitory dipeptide isoleucine-tryptophan. In a first step, a repetitive isoleucine-tryptophan construct fused to the maltose-binding protein was generated and expressed in Escherichia coli BL21 cells. The chromatographically purified recombinant fusion protein was enzymatically hydrolyzed using α-chymotrypsin to liberate the dipeptide isoleucine-tryptophan. The identity of the liberated isoleucine-tryptophan was confirmed by MS and derivatization of its N-terminus. The ACE-inhibitory effect of the recombinant dipeptide on soluble and membrane bound ACE was found to be indistinguishable from the inhibitory potential of the chemically produced commercially available dipeptide. The established experimental strategy represents a promising approach to the biotechnical production of sufficient amounts of recombinant peptide-based ACE-inhibitory and antihypertensive substances that are applicable as functional food additives to delay or even prevent hypertension.