SCORED SALT QUESTIONNAIRE AND URINARY ALBUMIN CREATININE RATIO IN A COHORT OF UNSELECTED MEXICAN PARTICIPANTS

Introduction:

High sodium intake has a well-established detrimental effect on kidney health. It has been constantly associated with increased blood pressure, poor cardiovascular outcomes and progression of kidney damage in chronic kidney disease (Borrelli, 2020). Hence, according to the World Health Organization, the reduction of sodium intake to less than 2.3 g/day and salt to less than 5.8 g/day is one of the most efficient and effective public health interventions (Malta, 2018). Approximately, 90% of dietary sodium is released through the urine. Thus, 24 hour urine sodium measurement is the gold standard to estimate sodium intake. However, this method is cumbersome and time consuming. As a result, food frequency questionnaires such as the Scored Sodium Questionnaire (SSQ) were developed. Moreover, paired with urine dipstick tests, they represent an acceptable alternative for kidney health screening. Herein we studied the relationship between SSQ and the urinary albumin creatinine ratio aiming to achieve a better understanding of the role of high sodium intake in kidney function.

Methods:

Data from FRENALA (a transversal study aiming to determine the factors that affect kidney health in the Mexican population) were analyzed. Previous approval from our institutional Ethics and Research Committee was granted. A multiple regression model was constructed to estimate the urinary albumin creatinine ratio (UACR) measured through dipstick test. The studied predictors were age, sex, BMI, xerosis, pruritus, hyperpigmentation, prematurity, confirmed COVID-19 infection, SSQ score, alcohol use, cardiovascular disease, smoking-pack years, hypertension, diabetes mellitus 2, nocturia and adverse childhood experiences. Both the statistical analysis and graphics were performed using STATA (v. 18.0; STATA Corp, College Station, TX, USA). 

Results:

A total of 151 participants of FRENALA were included. Confirmed COVID-19 infection (β = 100.3164, p = 0.039), alcohol use (β = 132.8316, p = 0.005), smoking pack-years (β = 49.0052, p = 0.001) and nocturia (β = 33.3039, p = 0.030) arose as statistically significant positive predictors of UACR. Conversely, SSQ score (β = -2.3463, p = 0.003) emerged as a negative predictor of UACR (Figure 1). The overall model resulted statistically significant (p = 0.0035) with an adjusted R2 of 0.30 (Table 1).

Conclusions:

COVID-19 infection, alcohol use, smoking pack-years and nocturia were positively related to UACR. However, higher SSQ score trended to smaller values of UACR. One explanation behind this apparently contradictory finding could be the relatively small sample size of our study. It is also possible that participants with the higher levels of UACR were actively avoiding sodium consumption. Nonetheless, more research is urgently needed to better determine the appropriateness of SSQ score as an alternative to screen patients for kidney damage, specially in developing countries where early and efficient CKD detection is a pressing need. 

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.