1. Introduction
Hypertension and T2D has become a global public health concern in the 21st century.Both diseases lead to severe complications such as chronic kidney diseases[1]and cardiovascular[2],which increase the risk of death over a long period of time. Both of them related to lifestyles such as physical exercise[3],alcohol consumption[4] , and dietary habits[5,6]. Studies have found that about 50% of T2D patients have hypertension, and 20% of hypertensive patients have T2D[7]. Hypertension coexists with T2D, which increases the risk of cardiovascular-related events and makes BP management more complicated and difficult[8]. Drug use alone makes BP control hard to achieve, so lifestyle intervention (such as dietary intervention and exercise) is more needed.
The DASH diet was proposed by National Heart, Lung, and Blood Institute (NHLBI) in 1977 to control the BP of hypertensive patients. The DASH eating plan encourages the consumption of potassium-rich vegetables and fruits, including whole grains, poultry, fish, and nuts, and reduces sodium and saturated fat intake[9]. There is strong evidence that the DASH dietary pattern can lower BP[10,11], including patients with T2D and hypertension[12,13].However, as the DASH diet was designed for white ethnicity, it is difficult for Chinese people to follow the original DASH diet. In addition, Chinese people generally prefer salty foods.It is estimated that Chinese people consume an average of 12g of salt per day[14],but DASH diet requires a daily consumption of 2300 mg of sodium (equivalent to 5.8 g of sodium chloride) or less[10], which also makes it difficult for the DASH diet to be used in Chinese population. Among many salt reduction strategies, consuming low-sodium salt is a feasible and low-cost method. Numerous studies have shown that low-sodium salt can lower BP by reducing sodium and adding potassium[15,16],but it has not been used in the DASH diet so far.
Therefore, in this randomized controlled trial, we developed a modified DASH diet for the use of Chinese people, and we want to know the hypotensive effect of 52% low-sodium salt applied to CM-DASH diet in patients with hypertension and T2D.