Journal of Pharmaceutical Negative Results ¦ Volume 13 ¦ Special Issue 9 ¦ 2022 1792 LACTOSE INTOLERANCE AND ITS EFFECT ON PLASMA GLUCOSE LEVELS AND OTHER BIOCHEMICAL PARAMETERS Masood Ali Qureshi 1 , Aneela Qureshi 2 , Arshad Ali Lakho 3 , Abdul Ghaffar Pirzado 4 , Saeed Ahmed Shaikh 5 , Shahzad Ali Jiskani 6* 1 Assistant Professor, Department of Community Medicine, Chanda Medical College @ SMBBMU, Larkana 2 Demonstrator, Department of Biochemistry, Chandka Medical College @ SMBBMU, Larkana 3 Senior Registrar, Department of Pediatrics, PUMHS Nawabshah 4 Assistant Professor Department of Surgery, Chandka Medical College @ SMBBMU, Larkana 5 Professor, Department of Community Medicine, Chandka Medical College @ SMBBMU, Larkana * 6 Assistant Professor, Department of Pathology, Chandka Medical College @ SMBBMU, Larkana Email: shahzadbaloach289@gmail.com DOI: 10.47750/pnr.2022.13.S09.215 Aim: To determine the effect of lactose intolerance on serum glucose levels and related biochemical parameters in the adult population who refrain from consuming milk and milk products. Material and Method: This retrospective, observational study was conducted in a tertiary care hospital between January 2021 and December 2021 with 296 participants. Plasma glucose, calcium, 25-hydroxyvitamin D3, folate, vitamin B12, thyroid- stimulating hormone (TSH), and ferritin levels were controlled. Patients with positive lactose intolerance test results were accepted as the study group and negative results were accepted as the control group, and data of two groups were compared. Results: Of the total 296 participants 212 (71.7%) were found to have lactose intolerance and 84 (28.3%) were found to be normal. In the lactose intolerant group, blood glucose levels were significantly lower than the control group (5.14±0.53 mmol/L versus 5.47±0.54 mmol/L, p<0.001). In the lactose intolerant group, 29 (13.7%) patients, and in the control group 18 (21.4%) patients were having type 2 diabetes mellitus. In diabetic patients, both fasting blood glucose (5.68±0.49 mmol/L versus 6.30±0.59 mmol/L, p<0.001) and glycated hemoglobin levels were also significantly lower than the control group in the study group (6.78±1.08 versus 7.62±0.96, p<0.001). Conclusions: In this study, based upon the findings of people with insufficient milk consumption, any decrease in blood calcium or vitamin D levels was not observed. Lactose intolerant people may have lower blood glucose levels compared to lactase persistent people. Larger- scale and long-term studies are needed to demonstrate that persistence of lactase is an independent risk factor for the development of diabetes. Keywords: Lactose intolerance, plasma glucose, biochemical parameters. INTRODUCTION Lactose is a disaccharide, found in milk and milk products, composed of simple sugars, glucose, and galactose. Lactase enzyme is needed in the degradation process. Decreasing enzyme activity during the lifetime may lead to less diabetes risk during adulthood theoretically. Enzyme activity of lactase decrease as time passes and in adulthood, the enzyme capacity decreases down to 30%. (1) Intestinal epithelial lactase enzyme deficiency causes insufficient degradation of lactose into glucose and galactose and results in lactose intolerance. (2-3) Due to flatulence and dyspepsia experienced after ingesting dairy products, many people presume that they have lactase deficiency and refrain from consuming lactose-containing foods, such as milk and milk products, although they, have no lactase enzyme deficiency. (4) According to statistical data of the year 2017, diabetes is an epidemic condition affecting 451 million people. (5) Treating diabetes is very important in many aspects of community health. The majority (over 90%) of diabetic patients are having type 2 diabetes mellitus. (6) Protective measures such as regular physical exercise and losing excess weight, and diet are key points in the treatment of type 2 diabetes mellitus. According to different trials, maltase, sucrase, and lactase enzyme activities are