Purpose:

The aim of this present study is to investigate the effect of vinegar consumption on 24-hour urinary risk factors associated with calcium oxalate urinary stone formation and blood biochemical parameters.

Methods:

The investigators will recruit 50 healthy young student volunteers in this study. By simple random sampling technique, volunteers will be allocated to two groups (group 1, control group; group 2, vinegar group).Each participant in vinegar group drink 15ml vinegar ( Ninghuafu, Sanxi, China) at noon and evening respectively for a period of four weeks.The end point of this study is comparison the outcomes of 24-hour urine and blood biochemical parameters between different group and point-in-time.

Purpose:

The written history of vinegar use in China was more than 5,000 years,and it was used as health care products since ancient times. In addition of the main component of acetic acid, it also contains other acids, esters, polyphenols and other active substances.Previous studies have reported some effects of vinegar, such as delays gastric emptying,relieves fatigue, regulates blood glucose and lipid metabolism, antioxidant, reduces blood pressure and so on. The China national epidemiological study of urolithiasis which was conducted from May 2013 through July 2014 indicated that vinegar may be protective against the formation of urolithiasis (has not been published). Animal experiments showed that vinegar could inhibit oxalate calcium crystal formation in rat kidneys (has not been published). Consequently, we performed this randomized controlled trial to investigate the effect of vinegar consumption on 24-hour urinary risk factors associated with calcium oxalate urinary stone formation and blood biochemical parameters.

Methods:

Study design and participants: We will recruit 50 healthy young student volunteers in this study. The inclusion criteria are male who age 18-35 years, and those with normal renal function,without urolithiasis and congenital urinary tract abnormalities. The exclusion criteria include hematuria, urinary tract infection and have a history of kidney or urinary diversion. We exclude male older than 35 years because usually they have to work and not easy to collect 24-hour sample. The reason of excluding female is that the trail will last four weeks and women's menstrual cycle could affect 24-hour urine collection.

Randomisation:

Trained research clinicians enroll volunteers in a university nearby our hospital. Volunteers will be allocated in a 1:1 ratio to control group(group 1) or vinegar group(group 2) by simple random sampling technique, which is conducted by clinical trial office in urology department of our hospital in Guangzhou, China.

Procedures: Each participant in vinegar group drink 15ml vinegar ( Ninghuafu, Sanxi, China) after dinner at noon and evening respectively for a period of four weeks,and participants in control group do not need intervention.All of participants drink vinegar under the surveillance of research clinicians.

Data collection:

Baseline data will be collected before randomization in our hospital. The baseline data protocol includes urinary ultrasonography, spot urine examines, 24-hour urine analysis and blood chemical examines. The parameters of 24-hour urine analysis include Ph, volume, creatinine, oxalate, citrate, phosphate, uric acid, calcium, magnesium, sodium and chloride. The standard blood analysis protocol included routine haematology, fasting serum glucose, creatinine, urea, uric acid, high-density lipoprotein, low-density lipoprotein, triglycerides, alanine transaminase(ALT), total protein(TP), albumin, glutamyltransferase (GGT) , serum total bile acid, cholesterol, sodium, potassium, calcium and chloride ions. Another tube of blood samples are freeze in -80 degree refrigerator for further analysis of oxidation of blood protein product(AOPP), malondialdehyde(MDA), glutathion peroxidase(GSH-PX), superoxide dismutase(SOD) and catalase activity(CAT).

Follow-up data include 24-hour urine analysis on the 7th, 14th, 21th and 28th day during this period and blood biochemical examines on the 29th day. The protocol of 24-hour urine and blood chemical examines is the same with baseline data. And participants will be asked to make a record of meals for seven days.The ANOVA for repeated measures is used to perform the data analysis.

Inclusion Criteria:

• Normal renal function.
• Those without urolithiasis
• Those without congenital urinary tract abnormalities.

Exclusion Criteria:

• Those with hematuria
• Those with urinary tract infection
• Those have a history of kidney or urinary diversion.