An efficient case finding strategy to diagnose osteoporosis in a developing society with low treatment frequency

The prevalence of patients treated for osteoporosis in Greenland is low compared to Denmark

The study is a register-based cross-sectional study aiming to estimate the prevalence of treated osteoporosis in Greenland compared to Denmark and provide a description of the patients with osteoporosis in Greenland. In addition, the study estimates the incidence of hip fractures in Greenland from 2018 to 2020 among people aged 65 years or older. The overall prevalence of patients prescribed medication for osteoporosis among those aged 18 years or older was 0.56% in Greenland and 2.36% in Denmark (p < 0.001). Among those aged 50 years or older, the prevalence was 1.28% and 4.71% in Greenland and Denmark, respectively (p < 0.001). The prevalence increased to 3.41% and 11.18% among patients aged 80 years or older in Greenland and Denmark, respectively. The incidence of hip fractures in Greenland was 6.55 per 1,000 inhabitants in 2020 compared to 5.65 per 1,000 inhabitants in Denmark (NS). In conclusion, the prevalence of treated osteoporosis in Greenland was less than one in four of that of Denmark. The incidence of hip fractures was similar in Greenland than in Denmark. Hence, our findings suggest that a marked number of subjects with osteoporosis in Greenland go untreated.

Hip geometry in hip fracture patients in Greenland occurring over a 7.7-year period

Background

Hip geometry influences hip fracture risk. Hip fractures are common, and they are associated with pain, disability, premature death and marked costs on society. Osteoporotic fractures are frequent in Arctic populations and increase with advancing age in this society with a steep rise in life expectancy. Greenland Inuit is a distinct ethnic group, and data on hip geometry is missing. We thus aimed to describe hip geometry in 7.7 years of consecutive hip fracture patients in Greenland.

Methods

We evaluated collodiaphysial angle, femoral neck length, the outer and inner diameter of the femur at 2 and 5 centimetres below the centre of the lesser trochanter and the cortical thickness from pelvic and hip radiographs in all patients operated in Greenland over 7.7 years. We included all 84 patients with one non-fractured hip visible for geometric analysis. Analyses were conducted in duplicate.

Results

We found a collodiaphysial angle of 134.8/132.6^o in men/women (p = 0.06) and a femoral neck length of 38.0/33.9 mm in men/women (p = 0.001). Cortical thickness was affected by sex in the adjusted analysis (p < 0.001). Cortical thickness index at 5 cm below the centre of the lesser trochanter decreased with age (p = 0.026) and may be influenced by height (2 cm below the centre of the lesser trochanter, p = 0.053).

Conclusion

Our findings differed from European data and suggest a delicate balance in hip geometry in Arctic populations. Ethnic peculiarities influence the structure of the hip and may influence fracture risk. A focus on hip geometry and risk factors for osteoporotic fractures in Arctic populations is warranted.

Serum 25-hydroxyvitamin D, calcium and parathyroid hormone levels in Native and European populations in Greenland

Ca homoeostasis is important to human health and tightly controlled by powerful hormonal mechanisms that display ethnic variation. Ethnic variations could occur also in Arctic populations where the traditional Inuit diet is low in Ca and sun exposure is limited. We aimed to assess factors important to parathyroid hormone (PTH) and Ca in serum in Arctic populations. We included Inuit and Caucasians aged 50-69 years living in the capital city in West or in rural East Greenland. Lifestyle factors were assessed by questionnaires. The intake of Inuit diet was assessed from a FFQ. 25-Hydroxyvitamin D (25OHD2 and 25OHD3) levels were measured in serum as was albumin, Ca and PTH. The participation rate was 95 %, with 101 Caucasians and 434 Inuit. Median serum 25OHD (99·7 % was 25OHD3) in Caucasians/Inuit was 42/64 nmol/l (25, 75 percentiles 25, 54/51, 81) (P<0·001). Total Ca in serum was 2·33/2·29 mmol/l (25, 75 percentiles 2·26, 2·38/2·21, 2·36) (P=0·01) and PTH was 2·7/2·2 pmol/l (25, 75 percentiles 2·2, 4·1/1·7, 2·7) (P<0·001). The 69/97 Caucasians/Inuit with serum 25OHD <50 nmol/l differed in PTH (P=0·001) that rose with lower 25OHD levels in Caucasians, whereas this was not the case in Inuit. Ethnic origin influenced PTH (β=0·27, P<0·001) and Ca (β=0·22, P<0·001) in multivariate linear regression models after adjustment for age, sex, BMI, smoking, alcohol and diet. In conclusion, ethnic origin influenced PTH, PTH response to low vitamin D levels and Ca levels in populations in Greenland. Recommendations are to evaluate mechanisms underlying the ethnic influence on Ca homoeostasis and to assess the impact of transition in dietary habits on Ca homoeostasis and skeletal health in Arctic populations.