Risk factors of colorectal cancer among Saudi Population: Case-control study.

BACKGROUND: Colorectal cancer (CRC) incidence and related mortalities have been steadily increasing in KSA over the past 20 years. CRC in the Kingdom of Saudi Arabia (KSA) population presents in younger ages and in more advanced disease states as compared to other countries. This study was aimed to determine factors (demographic, habitual, environmental, nutritional, and genetic) associated with CRC in Riyadh, KSA. MATERIALS AND METHODS: A matched case-control study conducted in the major hospitals in Riyadh (King Khalid university Hospital, King Faisal Specialist Hospital, Riyadh Military Hospital, Security Force Hospital, King Fahd Medical City). Here most of CRC cases are managed. The cases (n = 121) group included all recently diagnosed and pathologically confirmed Saudi cases of CRC identified during the period 1st of January 2017 till 31st of December 2018 who agreed to participate and fulfilled the inclusion criteria. A similar number of controls attending the study settings were selected consecutively from the clinics where cases were managed and matched on a 1:1 basis with cases based on age (+/-3 years) and gender. Data were collected using a structured questionnaire. Conditional logistic regression models were fitted to determine factors associated with risk of CRC. RESULT: This study included similar number of males and females in both groups: males 69 (57%) and females 52 (43%) in each group (Chi-square test P = 1.0). The mean (S.D) age in the cases group was 53.6 (S.D = 12.9) and 53.3 (S.D = 12.9) in the controls group (Student test P = 0.86). In the final multivariate conditional logistic regression model, variables independently associated with risk of colorectal cancer were body mass index (OR = 0.93; 95% CI 0.87-0.98; P = 0.011) employment status (inverse relation: OR = 0.33; 95% CI 0.14-0.77; P = 0.010), colon polyps (OR = 4.09; 95% CI 1.06-15.82; P = 0.041), and constipation (OR = 4.98; 95% CI 1.91-15.99; P = 0.001). CONCLUSION: Factors associated with CRC in the major referral hospitals in KSA were colon polyps, chronic constipation, and unemployment. These factors should be considered when screening for patients at risk for CRC.

A weekly 35,000 IU vitamin D supplementation improves bone turnover markers in vitamin D deficient Saudi adolescent females.

This study examined the effects of weekly 35,000 IU vitamin D supplementation for 4 weeks on bone turnover markers (BTMs). There was improvement in the levels of parathyroid hormone (PTH), osteocalcin, and carboxy-terminal telopeptides of crosslinks of type 1 collagen (ßCTX) which paralleled the increase in vitamin D levels. PURPOSE: The effects of vitamin D supplementation on bone turnover markers (BTMs) have been inconsistent. This study examined the effects of weekly 35,000 IU vitamin D supplementation for 1 month on BTMs. METHODS: Sixty-eight vitamin D deficient adolescent females were given 35,000 IU of vitamin D3 for 4 weeks. Pre and post intervention blood samples were taken for 25(OH) D, PTH, osteocalcin and ßCTX. RESULTS: There was a significant increase in serum 25 (OH) D in the post intervention period which was accompanied by a significant decrease in PTH, osteocalcin and ßCTX (P < 0.001). CONCLUSIONS: We concluded that weekly 35,000 IU vitamin D supplementation for 4 weeks results in significant improvement of BTMs.

Vitamin D deficiency and biochemical variations among urban Saudi adolescent girls according to season.

OBJECTIVES: To determine seasonal variations in the vitamin D status of Saudi adolescent girls in Riyadh, Kingdom of Saudi Arabia (KSA) and its effect in biochemical and clinical characteristics.  METHODS: In this prospective study, a total of 2000 Saudi females aged 12-18 years from different schools in Riyadh, KSA participated and submitted a generalized questionnaire with clinical information. Fasting blood samples were obtained in 1618 subjects for the winter season (December to February) and only 499 subjects returned to submit fasting blood samples for the summer season (June-August). Circulating serum 25(OH)D, parathyroid hormone (PTH), and other biomarkers of bone remodeling were measured during both seasons.  RESULTS: Vitamin D deficiency (serum 25(OH)D  less than 25 nmol/L) was significantly higher during summer than winter (63.5% versus 40.8%; p less than 0.001). Mean serum PTH was also significantly higher during summer than winter (p less than 0.01). In all subjects, serum PTH showed a significant inverse association with 25(OH)D at levels below 40 nmol/L (r=-0.21; p less than 0.001). The prevalence of subjects having clinical and metabolic manifestations suggestive of osteomalacia was 2.13% (N=33 out of 1548). CONCLUSION: Seasonal variations in the vitamin D status of Saudi adolescent females significantly modifies biochemical parameters as response to vitamin D status change. In the meantime, heightened public health awareness should be given to populations at higher risk for vitamin D deficiency.