Introduction Periodontitis is a chronic infection which occurs due to bacterial infection followed by host inflammatory response, leading to the demolition of the supporting tissues of the teeth. 1 The disease results in the detachment of gingiva, destruction of alveolar bone and is characterised by tooth mobility, gingival bleeding and formation of up to 4mm deep periodontal pockets. 1,2 This ailment affects about 20-50% of the total world population, but a comparatively higher occurrence has been seen in Asian countries, including Pakistan. 3,4 Several local studies have reported the prevalence of periodontal disease to be about 98%, with 31% having advanced periodontitis. 4,5 Though all individuals are equally susceptible to periodontitis, certain risk factors increase the disease incidence, its severity and progression in prone individuals. An understanding of such factors is necessary for proper disease management and improved patient outcomes. 1,6,7 "Modifiable" and "non-modifiable" risk factors have been found to be associated with periodontitis and are widely discussed in literature. 1,6,8 Modifiable factors are usually controllable that can either be environmental or behavioural. Socioeconomic status (SES), psychological stress, smoking, alcohol consumption, nutritional status, microbial infections due to poor oral hygiene, diabetes mellitus (DM), cardiovascular disease (CVD), drug-induced disorders and obesity are some of the established modifiable risk factors for periodontitis. 1,8 Non-modifiable factors are inherent aspects of an individual that can hardly be changed. These include genetic factors, host immune response, haematological disorders, hormonal changes, antioxidant imbalance, pregnancy, osteoporosis and ageing. 1,8 Micronutrients, such as vitamins and minerals, are known to play an important role in maintaining good bone health and keeping strong immunity. As the diagnosis of periodontitis depends only upon disease history and clinical examination, serum levels of micronutrients could aid in the prediction of the prognosis of periodontitis. Pakistan National Nutrition Survey, 2011 revealed severe micronutrient insufficiencies among children, pregnant and nursing women. 9 J Pak Med Assoc 252 RESEARCH ARTICLE Case-control study for assessment of factors associated with periodontitis among adults attending a university hospital in Karachi, Pakistan Sara Rafique, 1 Sadaf Khan, 2 Shahbaz Ahmed, 3 Masood Anwar Qureshi, 4 Rafat Amin 5 Abstract Objective: To compare the physiological and biochemical markers in healthy and periodontitis subjects, and to relate these markers with the periodontal health condition. Methods: The case-control study was conducted at the Dow University of Health Sciences, Karachi, from April 2017 to March 2018, and comprised systematically healthy controls and periodontitis cases. Periodontal probing depth, clinical attachment loss, oral hygiene indices, educational status and body mass index were recorded for all the subjects. Serum levels of biochemical markers, including calcium, phosphate and interleukin-6, were also measured. Data was analysed using SPSS 16. Results: Of the 150 subjects, 75(50%) each were in the case and control groups. The overall mean age was 31.23±3.7 years (range: 22-42 years). The cases had relatively poor oral hygiene indices and educational status compared to the controls (p<0.05). Serum calcium level was lower, whereas mean body mass index was higher in the cases compared to the controls (p<0.05). No significant difference was found in interleukin-6 and phosphate levels (p>0.05). Clinical attachment loss showed significant correlation (p<0.05). Conclusion: Low serum calcium and educational levels, higher body mass index and poor oral hygiene were found to be the risk factors for the progression of periodontitis. Keywords: Periodontitis, Serum calcium, BMI, Oral hygiene, Clinical attachment loss. (JPMA 71: 252; 2021) DOI: https://doi.org/10.47391/JPMA.568 1 Department of Physiology, Jinnah medical and dental college, Karachi, 3 Department of Operative Dentistry, Dr. Ishrat ul Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences, Karachi, 2,5 Dow College of Biotechnology, Dow Research Institute of Biotechnology and Biomedical Sciences, Dow University of Health Sciences, Karachi, 4 Department of Physiology, Dow International Medical College, Institute of Basic Medical Sciences, Dow University of Health Sciences, Karachi, Pakistan. Correspondence: Rafat Amin. Email: rafat.amin@duhs.edu.pk