Julia Chackathayil

Vitamin D deficiency amongst minority ethnic groups in the UK: a cross sectional study

BACKGROUND Vitamin D deficiency is common amongst minority groups in Britain but its magnitude amongst South Asian (SA) and Black African-Caribbean (AC) groups is not well defined. The steroidal, endocrine nature of vitamin D provides it with a putative link with cardiovascular disease (CVD), and we hypothesised that aberrant levels of this hormone would reflect a heightened risk of CVD in these ethnic groups. METHODS SA (n=1105, 57% male) and AC (n=748, 51% male) were recruited as part of a community heart failure study from 20 primary care practices, Birmingham, UK. Vitamin D2/D3 levels were measured to determine rates of total vitamin D status, which were age/sex adjusted. RESULTS The majority of SAs had severe vitamin D deficiency (42.2%, 95% CI: 39.2-45.1), which was more frequent than in AC (12.5%, 10.2-14.9, p<0.001. Vitamin status in SA and AC was unrelated to the presence of osteoporosis, and on multivariate analysis of SA, vitamin D levels were independently associated with age (β=0.18, p<0.001), haemoglobin (β=0.12, p=0.002), and negatively with alkaline phosphatase (a marker of bone mineralisation, β=-0.11, p=0.022). Amongst AC, vitamin D was independently associated with having ever smoked (β=-0.13, p=0.006) and systolic blood pressure (β=0.10, p=0.038). CONCLUSIONS Vitamin D deficiency is a frequent biochemical observation amongst minority groups in Britain but the clinical significance is unclear, and ethnically specific. A proportionate susceptibility to bone disease is not apparent in either minority group.

Cardiovascular Risk Profiles amongst Women in a Multiethnic Population in Inner City Britain: A Potential Impact of Anaemia

The risk of diabetes is markedly reduced in men with iron deficiency anaemia (IDA). The nature of this relationship in women is not clear, nor is there information about the influence of ethnicity, given the increased susceptibility of diabetes amongst South Asians and Afro-Caribbeans. We reviewed 3563 patients with a diagnosis of anaemia from 2000 to 2007. The age-adjusted prevalence of vitamin B12 deficiency and IDA was calculated, together with cardiovascular comorbidities amongst Caucasians, South Asians, and Afro-Caribbeans. The prevalence of vitamin B12 deficiency (women only) or IDA was markedly higher in South Asians compared to Caucasians and Afro-Caribbeans. Among women with IDA, diabetes was more prevalent among South Asians (45%, 95% CI 39.0–51.0) compared to Caucasians (3.0%, 2.1–4.0); P < 0.001. Among South Asian women with vitamin B12 deficiency, the prevalence of diabetes was reduced 8.5% (5.2–12.0). South Asian women with vitamin B12 deficiency had a higher prevalence of myocardial infarction (MI) and ischemic heart disease (IHD), but this relationship was reversed in IDA. IDA is associated with a greater prevalence of diabetes in South Asian women, but it is not coordinated by a greater risk of macrovascular complications. Given the cardiovascular impact of diabetes in South Asians, this association merits further study in relation to its pathophysiological implication.

Cardiac biomarkers: myths, facts and future horizons

Experts forecast a major worldwide epidemic of cardiovascular disease (CVD). It is believed that in 2020 CVD will over-run infectious disease and cancer to become the leading cause of death and disability, not only in industrialized countries, but also in the developing world. Therefore, in parallel with CVD treatment optimization, a considerable amount of effort is directed towards further development of preventive strategies. The keystone here may be the early identification of individuals with the highest risk. With wide adaptation of observations from cohort studies, several classical CVD risk factors have been incorporated into the clinical risk assessments. However, traditional risk factors cannot fully explain predisposition to CVD and the course of its recurrence in susceptible individuals. Thus, high expectations have been directed towards other additional or alternative pathways, which could provide clinically relevant information about CVD risk. Research is rapidly expanding in the field of cardiac biomarkers to assist risk stratification. Such information, provided by the measurement of various molecules and proteins in blood or urine, might expand our background knowledge about an individual’s risk of disease, and, thus, might bring the need for more appropriate actions to address this risk to the attention of health professionals. Biomarkers must fulfill specific requirements if they are to qualify for clinical use. In summary, the biomarker’s value above already known risk estimates should be consistently demonstrated in numerous prospective studies. However, to date, only a few cardiac biomarkers have fully satisfied these requirements and, consequently, have found widespread clinical utilization: these include blood cholesterol, glucose, creatine–phosphokinase and cardiac troponins (cTns). However, the evidence is accumulating in favor of a wider use of several novel biomarkers, such as C-reactive protein (CRP), B-type natriuretic peptides (BNP) and microalbuminuria, in the future. In addition, as our understanding of atherosclerosis pathophysiology expands and novel highthroughput molecular techniques (such as proteomics) find their place in cardiovascular research and clinical medicine, many fresh possibilities to help identify and characterize new cardiac biomarkers are on the horizon. This issue of Expert Review of Molecular Diagnostics provides a comprehensive overview on the detection of circulating biomarkers in CVD [1]. Given the intense interest into this topic, it is unsurprising that many myths exist among the true facts, and future horizons for current and novel biomarkers continue to be debated.

Ferritin as a Risk Factor for Glucose Intolerance amongst Men and Women Originating from the Indian Subcontinent

Background. Serum ferritin predicts the onset of diabetes; however, this relationship is not clear amongst South Asians, a population susceptible to glucose intolerance and anaemia. Objective. This study tests whether ferritin levels reflect glucose tolerance in South Asians, independent of lifestyle exposures associated with Indian or British residence. Methods. We randomly sampled 227 Gujaratis in Britain (49.8 (14.4) years, 50% men) and 277 contemporaries living in Gujarati villages (47.6 (11.8) years, 41% men). Both groups underwent a 75 g oral-glucose-tolerance test. We evaluated lifestyle parameters with standardised questionnaires and conducted comprehensive clinical and lab measurements. Results. Across sites, the age-adjusted prevalence of diabetes was 9.8%. Serum ferritin was higher amongst diabetics (P = 0.005), irrespective of site, gender, and central obesity (P ≤ 0.02), and was associated with fasting and postchallenge glucose, anthropometry, blood pressure, triglycerides, and nonesterified fatty acids (P < 0.001). Diabetes was less in those with low ferritin (<20 mg/mL), P < 0.008, and risk estimate = 0.35 (95% CI 0.15–0.81), as were blood pressure and metabolic risk factors. On multivariate analysis, diabetes was independently associated with ferritin (P = 0.001) and age (P < 0.001). Conclusion. Ferritin levels are positively associated with glucose intolerance in our test groups, independent of gender and Indian or UK lifestyle factors.

Corrigendum to “Ferritin as a Risk Factor for Glucose Intolerance amongst Men and Women Originating from the Indian Subcontinent”

[This corrects the article DOI: 10.1155/2015/924387.].

Subclinical thyroid dysfunction and cardiac function amongst minority ethnic groups in the UK: A cross sectional study

BACKGROUND Subclinical thyroid disease is associated with abnormal cardiovascular haemodynamics and increased risk of heart failure. The burden of raised/low thyroid stimulating hormone (TSH) levels amongst South Asian (SA) and African-Caribbean (AC) minority groups in the UK is not well defined. Given that these groups are particularly susceptible to CVD, we hypothesised that STD would reflect abnormal cardiac function and heightened cardiovascular risk in these ethnic groups. METHODS We examined SA (n=1111, 56% male, mean age 57.6 yrs) and AC (n=763, 44% male, mean age 59.2 yrs) participants from a large heart failure screening study. Euthyroidism is defined as TSH (0.4 - 4.9 mlU/l), subclinical hypothyroidism is defined as a raised TSH with normal serum free thyroxine (FT4) concentrations (9-19 pmol/l). Subclinical hyperthyroidism is defined as a low TSH with both FT4 and free triiodothyronine (FT3) concentrations within range (2.6-5.7 pmol/l). RESULTS Across ethnic groups, prevalence of subclinical hypothyroidism was 2.9% (95% CI 2.1-3.7), and of hyperthyroidism was 2.0% (1.4-2.7). Hyperthyroidism was more common amongst SA compared to AC (2.8% vs. 0.9%, P=0.017), while rates of subclinical hypothyroidism were similar. On multivariate analysis of variations in subclinical thyroid function, ethnicity was not independently significant. CONCLUSION The prevalence of subclinical thyroid disorders amongst SA and AC minority groups in Britain reflects levels reported in other populations. The clinical cardiovascular significance of subclinical thyroid disease is unclear, and it does not appear to be ethnically specific.