Vivek G Patwardhan1, Anuradha V Khadilkar2, Shashi A Chiplonkar1, Zulf M Mughal3, Vaman V Khadilkar1. 1. Growth and Endocrine Unit, Hirabai Cowasji Jehangir Medical Research Institute, Jehangir Hospital, Pune, India. 2. Growth and Endocrine Unit, Hirabai Cowasji Jehangir Medical Research Institute, Jehangir Hospital, Pune, India. Electronic address: anuradhavkhadilkar@gmail.com. 3. Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester, UK.
Abstract
BACKGROUND: Cholesterol and cholecalciferol are synthesized from a common substrate 7-dehydrocholesterol. 7-dehydrocholesterol is converted to cholesterol by 7-dehydrocholesterol reductase enzyme (DHCR7) and to cholecalciferol by ultraviolet B radiation from sunlight. OBJECTIVE: To examine the effect of sunlight exposure and serum DHCR7 levels on cholecalciferol and cholesterol levels and studying any interrelationship. METHODS: In a cross-sectional observational study, 307 apparently healthy men (aged 40-60 years) were assessed for sunlight exposure, lipid levels, serum DHCR7, 25 hydroxyvitamin D (25(OH)D), body composition, and dietary milk calcium intake. RESULTS: Vitamin D deficiency (25(OH)D <20 ng/mL, 1 ng/mL = 2.496 nmols/L) was found in 56% of subjects. Serum 25(OH)D concentrations increased significantly with increasing duration of sunlight exposure (P < .05). At lower sunlight exposure (<1 h/d), serum 25(OH)D levels were positively associated with high-density lipoprotein cholesterol (HDL-C) levels (P < .05) but at moderate sunlight exposure (1-2 h/d), there was no significant association. However, with higher sunlight exposure (>2 h/d), serum 25(OH)D concentrations were significantly negatively associated with HDL-C (P < .05). At moderate and higher sunlight exposure, an inverse significant relationship was observed between 25(OH)D and serum DHCR7 (P < .05); however, at lower sunlight exposure, no significant relationship was seen. CONCLUSIONS: 25(OH)D seems to show a varying relationship with HDL-C and serum DHCR7 at different durations of sunlight exposure.
BACKGROUND:Cholesterol and cholecalciferol are synthesized from a common substrate 7-dehydrocholesterol. 7-dehydrocholesterol is converted to cholesterol by 7-dehydrocholesterol reductase enzyme (DHCR7) and to cholecalciferol by ultraviolet B radiation from sunlight. OBJECTIVE: To examine the effect of sunlight exposure and serum DHCR7 levels on cholecalciferol and cholesterol levels and studying any interrelationship. METHODS: In a cross-sectional observational study, 307 apparently healthy men (aged 40-60 years) were assessed for sunlight exposure, lipid levels, serum DHCR7, 25 hydroxyvitamin D (25(OH)D), body composition, and dietary milk calcium intake. RESULTS:Vitamin D deficiency (25(OH)D <20 ng/mL, 1 ng/mL = 2.496 nmols/L) was found in 56% of subjects. Serum 25(OH)D concentrations increased significantly with increasing duration of sunlight exposure (P < .05). At lower sunlight exposure (<1 h/d), serum 25(OH)D levels were positively associated with high-density lipoprotein cholesterol (HDL-C) levels (P < .05) but at moderate sunlight exposure (1-2 h/d), there was no significant association. However, with higher sunlight exposure (>2 h/d), serum 25(OH)D concentrations were significantly negatively associated with HDL-C (P < .05). At moderate and higher sunlight exposure, an inverse significant relationship was observed between 25(OH)D and serum DHCR7 (P < .05); however, at lower sunlight exposure, no significant relationship was seen. CONCLUSIONS: 25(OH)D seems to show a varying relationship with HDL-C and serum DHCR7 at different durations of sunlight exposure.
Authors: Vivek G Patwardhan; Zulf M Mughal; Raja Padidela; Shashi A Chiplonkar; Vaman V Khadilkar; Anuradha V Khadilkar Journal: Indian J Endocrinol Metab Date: 2017 May-Jun
Authors: Vivek G Patwardhan; Zulf M Mughal; Shashi A Chiplonkar; Ann R Webb; Richard Kift; Vaman V Khadilkar; Raja Padidela; Anuradha V Khadilkar Journal: Indian J Endocrinol Metab Date: 2018 Mar-Apr
Authors: Javier Rodríguez-Carrio; Mercedes Alperi-López; Manuel Naves-Díaz; Adriana Dusso; Patricia López; Francisco Javier Ballina-García; Jorge B Cannata-Andía; Ana Suárez Journal: Sci Rep Date: 2019-02-22 Impact factor: 4.379