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CDDS Centre for Developmental Disability Studies. Sunlight skin cancer and bones: Making sense of “mixed” messages Seeta Durvasula Centre for Developmental Disability Studies University of Sydney seetad@med.usyd.edu.au. Sun exposure and skin cancer.
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CDDS Centre for Developmental Disability Studies Sunlight skin cancer and bones:Making sense of “mixed” messages Seeta Durvasula Centre for Developmental Disability StudiesUniversity of Sydneyseetad@med.usyd.edu.au
Sun exposure and skin cancer • 1920s – attitudes to sunlight exposure • seen as health promoting • “tanned is beautiful” • In Australia, sun exposure causes • 99% of non-melanoma skin cancers • 95% of melanomas (Armstrong, 2004) • So, strong public health campaigns for sun protective measures
Sun Protection Measures • Minimise time in the sun between 11am and 3pm (daylight saving time); • Use shade wherever you can including trees, shelters and umbrellas; • Slip! on a shirt made from tightly woven fabric, with sleeves and a high neck or collar and other clothing that covers the skin; • Slop! on a broad spectrum water resistant sunscreen with an SPF rating of 30+; and • Slap! on a wide brimmed hat or legionnaire's cap, that shades the face, neck and ears. NSW Health, 1999
“Slip, Slop, Slap” Slip, Slop, Slap!It sounds like a breeze when you say it like thatSlip, Slop, Slap!In the sun we always say "Slip Slop Slap!“ Slip, Slop, Slap!Slip on a shirt, slop on sunscreen and slap on a hat,Slip, Slop, Slap!You can stop skin cancer - say: "Slip, Slop, Slap!" The Cancer Council Australia
Vitamin D and Bones • Hormone • Necessary bone health • helps absorb calcium from gut • Beneficial effect on muscle strength and balance • Prevention of fractures in elderly • May also have beneficial effects on some types of cancer
Where do you get it? (Vitamin D) • In Australia, 90% from sunlight - UVB • Food - minor source of Vitamin D in Australia • milk, cheese • margarine • liver • oily fish –sardines, mackerel, salmon
Pancreatic cells non classical classical
What is Vitamin D Deficiency?(Position statement, 2005) • Defined by serum Vitamin D level • Mild Vitamin D deficiency – • 25 (OH) vitamin D level - 25 – 50 nmol/L = Insufficiency • raised parathyroid hormone level • Moderate Vitamin D deficiency 12.5-25 nmol/L • Severe Vitamin D deficiency < 12.5 nmol/L
Vitamin D deficiency • Increase in parathyroid hormone release of calcium from bones • Reduced bone density • osteomalacia in adults • rickets in children • Increased fracture risk in older people • Muscle pains, muscle weakness • Linked to falls in older people • Associated with Type 1 diabetes, some cancers
Causes of Vitamin D deficiency • Inadequate sunlight exposure • elderly – especially in aged care facilities • immobility • skin covering • Sunlight less effective • ageing skin • pigmented skin • Diet – low consumption • Malabsorption and abnormal gut function
How common is vitamin D deficiency? • General population • 43% in young women - Geelong (Pasco et al. 2001) • 23% in adult population - SE QLD (McGrath et. Al, 2001) • Specific groups at risk • elderly in high level care – 55% (Flicker et al. 2003) • dark skin pigmentation, especially if also covered/veiled • 80% in one study (Grover & Morley, 2001)
People with developmental disability • Studies mainly in institutionalised populations on anticonvulsant therapy • 47% of people with developmental disability living in institution in NSW (Beange et al. 1994) • 57%of those in a residential facility in SA– those with poor mobility, difficulty in taking solids (Valint & Nugent, 2006) • Community living adults - 36% men and 40% women (Centre et al. 1998) • 43% of a clinic population in Sydney – older people, people with Down syndrome, overweight(Durvasula et al. 2005 - unpublished)
Prevention of Vitamin D deficiency in general population • Diet • 200IU if < 50yrs; 400IU if 51-70 yrs; 600 IU if >70yrs (US Food &Nutrition Board) • Most Australians get <100 IU/day • Sun exposure = 1/3 Minimal Erythema Dose (MED) • To Reduce fracture risk in elderly – 1000IU day
Recommended sun exposure • 1 minimal erythema dose (MED) is amount of sun exposure which produces faint skin redness =Whole body exposure to 10-15mins of midday sun in summer = 15,000U of vitamin D • Recommend1/3 MED = exposing hands, face and arms to of sunlight on most days
Recommended sun exposure times (mins) for 1/3MED for moderate fair skin Region Dec-Jan July-Aug at 10 am or 2pm Auckland 6-8 30-47 Christchurch 6-9 49-97 Cairns 6-7 9-12 Brisbane 6-7 5-19 Adelaide 5-7 25-38 Perth 5-6 20-28 Sydney 6-8 26-28 Melbourne 6-8 32-52 Hobart 7-9 40-47
Sun exposure in people with developmental disability • Paucity of reliable data except for those physical disability, or those in institutional care • Possible other at risk groups • e.g those with challenging behaviour, autism • Note: Reliance on carers/ support staff
Mixed messages? • Sun protection – prevent skin cancer • Sun exposure – prevent vitamin D deficiency
Not so “mixed” Risks and Benefits of Sun Exposure (2005) Aust. and NZ Bone Society, Osteoporosis Australia, Australasian College of Dermatologists, The Cancer Council of Australiahttp://www.cancer.org.au/content.cfm?randid=299825
Recommendations • Sun protection required when UV index is moderate or higher (≥3) • Most people achieve adequate Vitamin D levels through typical day to day activities, without deliberately seeking additional sun exposure • summer – expose face, arms and hands to average of 5 minutes most days of the week outside peak UV levels • winter, in Southern States – exposure of hands, face, arms for 2-3 hours over a week • Use of solaria not recommended due to level of UV exposure
Recommendations • Those at increased risk of skin cancer need more vigorous sun protection practices and should discuss their vitamin D requirements with their doctor • Those at increased risk of Vitamin D deficiency should discuss their vitamin D status with their doctor
Recommendations – special groups • Older adults – if not at high risk of skin cancer, ensure incidental exposure • Skin type – dark skin pigmentation, especially if covered – may need vitamin D supplementation
What about sunscreen? • Necessary to prevent skin damage if prolonged exposure (long enough to cause erythema) is planned • For incidental exposure, of less than 10 minutes, may be able to omit sunscreen • short exposures better for vitamin D synthesis (Nowson et al, 2004)
What about people with developmental disability? • Recommendations as for general population for prevention of vitamin D deficiency • i.e. safe sun exposure • But, need to take into account skin type/pigmentation, latitude, season, medication use (anticonvulsants), mobility
What about people with developmental disability? • However, many are at increased risk of Vitamin D deficiency e.g. • Medications • Limited sun exposure • poor mobility • staffing limitations • challenging behaviour • Therefore, incidental sun exposure may not be enough
Recommendations • Vitamin D insufficiency is common in people with developmental disability and can only be confirmed by measuring 25OH D • Either monitor yearly at end of winter (lowest values) and treat those < 50nmol/L with vitamin D supplements • Optimal calcium intake also needed – diet or supplements
Message not so “mixed” • Incidental safe sun exposure where possible • Check Vitamin D levels and treat if required • Need further research • Identify those with developmental disability who are especially at risk • Determine levels of sun exposure in those living in the community
Management Vitamin D Deficiency • 3000 – 5000 IU/day ergocalciferol for 6-12 weeks • 50 000 IU cholecalciferol. One tablet monthly for 3-6 months (NZ only) • Reassess after 3-4 months of treatment • 1000 IU/day of ongoing treatment required for most patients • Contraindicated in hypercalcaemia