## 1 Introduction  
Saliva is a complex biofluid which lubricates, nourishes, and maintains the health of the oral cavity. Saliva is comprised of a wide variety of enzymes, proteins, chemokines, cytokines, and electrolytes, which are important for performing different functions such as digestion, lubrication, taste, swallowing, and immune response [1]. On average, 300 mL of unstimulated whole saliva (UWS) is produced in a day and the salivary flow rate (SFR) is 0.1-0.3 mL/min. At rest or during sleep the SFR is estimated to be zero. Nearly 80-90% of daily secretion is stimulated and the average stimulated SFR is 1.5-7 mL/min [2; 3]. Salivary components are reported to vary due to oral conditions such as periodontitis, lichen planus, and oral submuc fibrosis, and salivary flow, pH, and composition are critical for maintaining the health of the oral cavity [4; 5; 6; 7]. Systemic conditions such as Diabetes Mellitus, hypertension, Grave's disease, and osteoporosis are also reported to influence salivary flow and constituents [8]. Diabetes Mellitus (DM) is caused by poor glycaemic control, and it is a risk factor for the multi-system disorder. According to the International Diabetes Foundation, Diabetes Atlas 9 th Edition, Pakistan has reached a diabetic prevalence of 17.1%. It has been estimated that 19 million adults in Pakistan will be suffering from diabetes by 2025, which will increase the risk of life-threatening complications [9]. Diabetes Mellitus type I (T1 DM) is due to the primary failure of the pancreatic beta cells to produce insulin, while Diabetes Mellitus type II (T2 DM) is caused by a failure of the insulin signaling mechanism in the target cells of the body. A reduction in salivary flow rate, pH, and xerostomia has been reported in patients with T2 DM, which is a potential cause of increased incidence of caries and oral infections [10]. Periodontitis is an inflammatory condition of periodontal tissues and its incidence in the Pakistani population is reported to be 25.9% [11]. Poor glycemic control in T2 DM increases the risk of periodontitis by approximately three-fold when compared to non-diabetic patients [12]. It has been reported that patients with T2 DM have increased levels of advanced glycation end products (AEGs) and inflammatory cytokines in their serum and periodontal tissues, which influences the periodontal tissues and exacerbates the process of periodontitis [13]. With an increase in studies on salivary diagnostic procedures, changes in the levels of amylase and glucose have been studied, showing increased salivary amylase levels among T2 DM people [14; 15; 16]. Hypertension (HTN) is another chronic condition, which is a risk factor for cardiovascular disorders, cerebrovascular disease, and renal disorders with a high mortality rate [17]. HTN is a cause of the deteriorated periodontal condition of the oral cavity and is one of the potential causes of gingival inflammation, bleeding, and chronic periodontitis leading to tooth loss [18]. A recent systematic review confirmed a positive relationship between HTN and periodontitis reported an increased incidence of severe periodontitis in patients with HTN [14]. Similarly, an improvement in periodontal health leads to a reduction in blood pressure [19]. Alterations within the salivary components have also been reported in hypertensive patients, and [PERSON] et al. suggested a significant influence of antihypertensive drugs on the salivary amylase levels [20]. Mucins are an important component of saliva and perform the function of lubrication as well as microbial binding. The mucins line the oral mucosa, prevent direct damage to the mucosa, and play a role in caries reduction [21]. Patients suffering from T2 DM and hypertension have reported an increased incidence of caries and oral infections [22]. It has been reported that periodontitis decreases the salivary flow rate and causes an increased output in protein levels, particularly mucins, which is believed to impart a protective influence to prevent oral infections [23].