Mart Kull

Seasonal variance of 25-(OH) vitamin D in the general population of Estonia, a Northern European country

BackgroundVitamin D has a wide variety of physiological functions in the human body. There is increasing evidence that low serum levels of this vitamin have an important role in the pathogenesis of different skeletal and extra-skeletal diseases. Vitamin D deficiency and insufficiency is common at northern latitudes. There are few population-based studies in the northern European region looking at the issue in a wider age group. We aimed to measure Vitamin D level in the general population of Estonia (latitude 59°N), a North-European country where dairy products are not fortified with vitamin D.MethodsThe study subjects were a population-based random selection of 367 individuals (200 women and 167 men, mean age 48.9 ± 12.2 years, range 25–70 years) from the registers of general health care providers. 25-(OH) vitamin D (25(OH)D) level and parathyroid hormone (PTH) were measured in summer and in winter. Additionally age, sex, body mass index (BMI) and self-reported sunbathing habits were recorded.ResultsThe mean serum 25(OH)D concentration in winter was 43.7 ± 15 nmol/L and in summer 59.3 ± 18 nmol/L (p < 0.0001). In winter 73% of the subjects had 25(OH)D insufficiency (25(OH)D concentration below 50 nmol/L) and 8% had deficiency (25(OH)D below 25 nmol/L). The corresponding percentages in summer were 29% for insufficiency and less than 1% for deficiency. PTH reached a plateau at around 80 nmol/L. BMI and age were inversely associated with 25(OH)D, but lost significance when adjusted for sunbathing habits. A difference in the seasonal 25(OH)D amplitude between genders (p = 0.01) was revealed.ConclusionVitamin D insufficiency is highly prevalent throughout the year in a population without vitamin D dairy fortification living at the latitude of 59°N.

Body mass index determines sunbathing habits: implications on vitamin D levels.

Vitamin D is crucial for calcium and bone metabolism. Overweight people have been found to have lower levels of this vitamin. The aim of the paper was to test if sun exposure habits might differ according to weight and body fat per cent in a random population‐based sample, and have an impact on vitamin D levels. The analysis of 367 persons showed that, among other established factors, differences in sunbathing also explain the lower vitamin D levels in overweight and elderly individuals.

Impact of molecularly defined hypolactasia, self-perceived milk intolerance and milk consumption on bone mineral density in a population sample in Northern Europe

Objective. Milk intake as a source of calcium is considered an important factor for bone mineral metabolism. Low lactase activity in adult-type hypolactasia (HL) and self-perceived lactose intolerance (LI) are the main limiting factors of milk intake. The aim of this study was to examine the relationship of HL, LI, individual milk consumption and bone mineral density in a population with high milk consumption and a prevalent vitamin D deficiency. Material and methods. A population-based study of 367 men and women aged 25–70 years was conducted in Estonia. HL was diagnosed by direct sequencing of the LCT gene, bone mineral density and body composition measured by dual energy X-ray absorptiometry (DXA). An original health questionnaire was used to collect data on milk and dairy consumption, self-perceived milk intolerance, supplement usage and fracture history. Results. Lactase genotype and phenotype had no effect on bone mineral density in this high milk consumption population with a prevalent vitamin D insufficiency. Milk consumption was a significant determinant of bone mineral density in Estonia. Self-perceived milk intolerance leads to self-imposed reductions in milk consumption, increases in bone turnover and an increased risk of fracture. Conclusions. Self-perceived milk-intolerance rather than HL influences milk consumption and has deleterious effects on bone metabolism.

Impact of a New Sarco-Osteopenia Definition on Health-related Quality of Life in a Population-Based Cohort in Northern Europe

Sarcopenia has been shown to be a marker of falling; therefore, combining osteopenia and sarcopenia could identify a frailer, higher-fracture-risk population. We aimed to define sarco-osteopenia (SOP) in a population-based healthy young sample using both muscle functional and quantitative parameters and assessing the impact of this definition on health-related quality of life. A population sample of 304 patients aged 25-70 yr was analyzed with a Lunar DPX-IQ dual-energy X-ray absorptiometry machine (GE Healthcare, Pollards Wood, UK), and their health-related quality of life was assessed with the Short-Form-36 (SF-36) questionnaire. SOP was defined as bone mineral density (BMD) -1 standard deviation (SD) and height-adjusted appendicular muscle mass -2 SD and/or grip strength -2 SD less than the mean values of 77 young individuals in the population sample (age: 25-39 yr). Our proposed SOP definition identifies 3-9% of the population older than 40 yr as sarco-osteopenic. These individuals also show markedly lower scores in the role-physical (p=0.01), vitality (p=0.03), and role-emotional (p=0.02) subscales of the SF-36 questionnaire. No difference in the quality of life was observed between osteopenic individuals and those with normal BMD. The new definition identifies a population with significant decrements in health-related quality of life.

Myotonometry demonstrates changes of lingual musculature in obstructive sleep apnoea

Upper airway dilator muscles are important in the pathogenesis of obstructive sleep apnoea (OSA). Previously, soft palate and tongue muscles of patients with OSA have been studied from a histological point of view. Electromyographic studies revealed increased activity of upper airway dilator muscles. We used computerized endopharyngeal myotonometry (CEM) to measure the biomechanical properties of lingual musculature, mainly the genioglossal muscle, to characterize changes of tongue muscles in patients with OSAS. The method records and analyzes the response of the tongue sublingually after a brief mechanical impact. It enabled us to evaluate the most important parameters of tissue tone – stiffness, which is expressed as a frequency, and elasticity, as a logarithmic decrement of the damped oscillation. The results of CEM indicated that patients with OSAS show an increased stiffness (14.1 ± 0.7 Hz) of the tongue in comparison with non-snoring subjects (11.5 ± 0.2 Hz). The elasticity of the tongue is decreased, which is numerically expressed as an increased decrement (4.0 ± 0.2) in patients with OSA in comparison with non-snorers (2.2 ± 0.2). Changes in the biomechanical characteristics of lingual musculature during wakefulness could result from pathophysiological processes caused by obstructive sleep apnoea.

Splice variant IVS2-2A>G in the SLC26A5 (Prestin) gene in five Estonian families with hearing loss

OBJECTIVE The aim of our study was to identify the IVS2-2A>G sequence change in the SLC26A5 (Prestin) gene in Estonian individuals with hearing loss and in their family members. METHODS In the years 2005-2007 we have screened 194 probands with early onset hearing loss and 68 family members with an arrayed primer extension (APEX) microarray, which covers 201 mutations in six nuclear genes (GJB2, GJB6, GJB3, GJA1, SLC26A4, SLC26A5) and two mitochondrial genes encoding 12S rRNA and tRNA-Ser (UCN). RESULTS In four probands with early onset hearing loss and in five unaffected family members from five families we identified the IVS2-2A>G change in one allele of the SLC26A5 gene. We did not find any homozygosity for this splice variant. IVS2-2A>G was identified in 2.1% of probands. One of these probands, however, is also homozygous for the 35delG mutation in the GJB2 gene and a second patient has Down syndrome, which is also associated with hearing impairment. Therefore, in those two cases the etiology of the hearing loss is probably not associated with the IVS2-2A>G sequence change in the SLC26A5 gene. CONCLUSION Our data support the hypothesis that heterozygosity for the mutation IVS2-2A>G in SLC26A5 gene may not, by itself, be sufficient to cause hearing loss.

Bone Mineral Density Reference Range in Estonia: A Comparison With the Standard Database (NHANES III)

Dual-energy X-ray absorptiometry (DXA) is accepted as a standard for diagnosing osteoporosis. Several databases are available for T-score calculation worldwide. Our aim was to compare hip bone mineral density (BMD) in young Estonian adults with the mean BMD in the National Health and Nutrition Examination Survey (NHANES) femur database and to compare the performance of these 2 databases. A population sample of 304 subjects was analyzed with a Lunar DPX-IQ DXA machine (GE Lunar Co., Madison, WI). Seventy-seven healthy young individuals were selected based on their age (25-39 yr). Their femur neck, trochanter, and total hip mean standardized BMD was compared with the corresponding data from the NHANES III database. Diagnostic agreement was assessed in a population sample of adults and in a clinical convenience sample from the densitometry unit. The BMD in the proximal femur in healthy young Estonian adults did not differ from the mean BMD in the NHANES subjects (p > 0.05). Differences in diagnosing osteoporosis and osteopenia are present if the Estonian reference database is used instead of the US standard database. Prospective studies with fracture data for assessing the predictive capability of these reference databases and the additional benefit of adding the FRAX (World Health Organization Collaborating Centre for Metabolic Bone Diseases, University of Sheffield, UK) tool to fracture prediction and osteoporosis diagnosis are needed in Estonia.

Macroscopic oropharyngeal signs indicating impaired defensive function of palatine tonsils in adults suffering from recurrent tonsillitis.

The present study explored in adults suffering from recurrent tonsillitis the association between macroscopic oropharyngeal signs of recurrent inflammation, immunomorphology of palatine tonsils (counts of neutrophils by CD4 and macrophages by CD68 monoclonal antibodies in tonsillar microcompartments) and the occurrence of post‐tonsillectomy bacteremia. The study involved 50 adults (31 females and 19 males) with recurrent tonsillitis. According to predominance of either inflammatory changes or evidence of sclerotic process in palatine tonsils and surrounding tissue macroscopic at oropharyngeal examination, the patients were divided into groups with ‘inflammatory‐type’ and ‘sclerotic‐type’ tonsils. Biochemically detected mean collagen content was significantly higher in ‘sclerotic‐type’ tonsils than in ‘inflammatory‐type’ tonsils (p=0.001). Post‐tonsillectomy bacteremia was found in 22 patients (44%). A noteworthy finding was the higher recovery of anaerobes from blood cultures than in previous studies. A logistic regression analysis revealed that the post‐tonsillectomy bacteremia was strongly associated with ‘sclerotic‐type’ tonsils (p=0.0015) and with low counts of neutrophils in tonsillar tissue (p=0.047). We conclude that macroscopic oropharyngeal signs of sclerotic process in palatine tonsils indicate impaired tonsillar defense, in terms of lowered counts of neutrophils, increasing the risk of post‐tonsillectomy bacteremia.

Adverse lifestyle and health-related quality of life: gender differences in patients with and without chronic conditions

Objectives: The aim was to investigate the relationship between the main lifestyle-related factors and health-related quality of life (HRQoL) in a sample of patients with and without chronic conditions (CCs) with respect to the gender differences in both groups. Methods: A cross-sectional study was conducted on 1061 patients (of which 308 had no CCs and 753 of those had one or more CCs) recruited at primary health care centres and the Internal Medicine Clinic at Tartu University Hospital in Estonia. Data were collected during 2012–2014. The patient’s age, self-reported smoking status, alcohol consumption (assessed by Alcohol Use Disorders Identification Test) and body mass index were used as independent variables to predict the physical component scores (PCS) and mental component scores (MCS) of HRQoL (assessed by SF-36). Results: Smoking had a negative association with both physical and mental components of HRQoL only in women with CCs. Further, the PCS of chronically ill women was negatively associated with the higher body mass index. Harmful drinking had a negative association with the HRQoL in all patient groups, except with the PCS in women with CC. Light alcohol consumption without symptoms of harmful use or dependency had a positive association with the physical and mental HRQoL in all patient groups, except with the MCS in women without CCs. Conclusion: Adverse lifestyle had the most expressed association with HRQoL in women with CCs. Light alcohol consumption had a positive association, but harmful use of alcohol had an inverse association with HRQoL irrespective of patients’ gender or health status.

Selection of indicators for tonsillectomy in adults with recurrent tonsillitis

BackgroundWe aimed to find some new indicators for tonsillectomy (TE) in adults with recurrent tonsillitis (RT) by exploring whether the frequency of tonsillitis episodes and the length of morbidity period are associated with the macroscopic signs of sclerotic process in tonsils and microbiological data assessed by culture, molecular (PCR) and transmission electron microscopy (EM) methods.MethodsThe study involved 62 RT patients admitted for TE (age range 15–35, median 22 years) and 54 healthy volunteers (age range 18–24, median 20 years). The index of tonsillitis (IT) was calculated by multiplying the number of tonsillitis episodes per year by the morbidity period in years. On oropharyngeal examination the presence or absence of three sclerotic signs was evaluated: tonsillar sclerosis, obstruction of tonsillar crypts and scar tissue on the tonsils. The occurrence of Streptococcus pyogenes was assessed by culture and PCR methods in 24 tonsillar core specimens. The samples for EM investigation of crypt epithelium were taken from 10 removed tonsils.ResultsThe IT values were in positive correlation with the number of sclerotic signs on oropharyngeal examination (r = 0.325, P = 0.010). Based on the IT values and the presence or absence of tonsillar sclerosis and obstruction of tonsillar crypts the receiver-operating curve (ROC) was constructed. It revealed that an IT score of 36 is an optimal cut-off value for prediction of sclerotic type tonsils. S. pyogenes was never found by culture, but its presence by PCR in nearly one third (29%) of diseased tonsillar tissue specimens was tightly associated with longer morbidity. EM revealed coccoid forms of intracellular bacteria in the crypt epithelium, which was accompanied with the damage of tight junctions between epithelial cells.ConclusionThe index of tonsillitis ≥36, being a combination between the frequency of tonsillitis and the length of morbidity period, predicts the sclerotic process in recurrently inflamed tonsils. Therefore, the high IT values could serve as an indicator for TE in adults. The correlation between the longer morbidity period and the presence of S. pyogenes by PCR suggests that persistent infection may have a role in maintenance of recurrent inflammation in tonsils.