Does consanguinity lead to decreased incidence of breast cancer?

BACKGROUND: In the Middle East region, consanguinity remains to be a central feature where it has shown an increasing trend. Breast cancer is an extremely complex disease, characterized by a progressive multistep process caused by interactions of both environmental and genetic factors. AIM: The aim of this study was to examine the possible effect of consanguinity on the risk of breast cancer in a population with a high rate of consanguinity and find the associated risk-modifying factors. SUBJECTS AND METHODS: The study included 167 Qatari and other Arab expatriates women with breast cancer and 341 age and ethnicity matched control women. A questionnaire that included the socio-demographic information, type of consanguinity, medical history, life style habits, dietary intake and tumor grade was designed to collect, the information of cases and controls. A total number of 214 breast cancer patients were approached and 167 cases completed the questionnaires with a response rate of 78%. Of the 417 healthy women who agreed to participate in this study, 341 responded to the questionnaire (81.8%). RESULTS: The study revealed that the rate of parental consanguinity was lower in breast cancer patients (24%) than in controls (32.3%) (p=0.062). Female controls were slightly younger (46.5+/-11.9) than breast cancer patients (48.4+/-10.7). Breast cancer incidence was significantly higher in Qatari women (34.1%) compared to other Arab women (65.9%) (p=0.034). A significant difference was noted only in occupation of the studied women between cases and controls (p<0.001). Overweight (46.7%) and obesity (32.9%) were significantly higher in female breast cancer patients compared to controls (p=0.028). Overall, the mean coefficient of consanguinity was lower in breast cancer patients (0.014) than in controls (0.018) (p=0.0125). Family history of breast cancer was significantly more often in breast cancer patients (14.4%) than in controls (6.2%) (p=0.002). However, the family history of breast cancer was more often positive in cases of non-consanguineous parents (15.7%) than cases of consanguineous parents (10.0%). CONCLUSION: The present study revealed the lack of association between of breast cancer and the parental consanguinity in Arab women residing in Qatar. The family history of breast cancer and the body mass index (BMI) are highly associated with breast cancer.

Impact of consanguinity on cancer in a highly endogamous population.

BACKGROUND: Many epidemiological studies have indicated that inbreeding has little or no effect on the incidence of cancer. Due to the high prevalence of consanguinity in Qatar (54%), its influence may nevertheless be of special importance. AIM: The aim of this study was to examine whether parental consanguinity affects the risk of cancer in a local Arab highly inbred population. DESIGN: Matched case-control study. SETTING: The study was carried out in Al-Amal cancer hospital and primary health care centers in Qatar over a period from August 2008 to February 2009. SUBJECTS AND METHODS: The study included 370 Qataris and other Arab expatriates with various types of cancers and 635 controls matched by age and ethnicity. A questionnaire that included socio-demographic information, type of consanguinity, medical history, and tumor grade was designed to collect the information of cases and controls. RESULTS: The study revealed that the rate of parental consanguinity was similar in both cases (29.5%) and controls (29.9%) with a higher inbreeding coefficient in controls (0.017-/+0.03), compared to cancer patients (0.0155-/+0.03). Other Arab expatriates had a higher incidence of cancer (61.1%) than Qataris (38.9%). The inbreeding coefficient was higher in male cancer patients (0.0189-/+0.03), but lower in female cancer patients (0.014-/+0.03) as compared to controls. Controls were more inbred in the overall studied subjects (23.6%) and women (23.8%) than cases. The coefficient of inbreeding was lower in patients with breast (0.014), skin (0.012), thyroid (0.008) and female genital (0.014) cancers, whereas it was higher in cases for leukemia and lymphoma (0.018), colorectal (0.025) and prostate (0.017), with no significant difference between cases and controls. No significant differences were observed between cases and controls in the parental consanguinity, mean coefficient of inbreeding and proportion of more inbred subjects. CONCLUSIONS: The study findings revealed that although the consanguinity rate is high in our Arab population, it has no effect on the incidence of cancers overall. However, there was an increased risk found for leukemia and lymphoma, colorectal and prostate cancer groups, but a reduced risk in breast, skin, thyroid and female genital cancer groups.

High prevalence of vitamin D deficiency in type 1 diabetes mellitus and healthy children.

Epidemiological studies suggest a link between vitamin D deficiency in early life and the later onset of type 1 diabetes. The aim of this matched case-control study was to find the association between vitamin D and T1DM then to study the difference in the level of vitamin D in T1DM and healthy subjects, and to determine the associated environmental risk factors in young Qatari population. The study was carried out among T1DM children and healthy subjects below 16 years at the pediatric endocrinology outpatient clinics of the Hamad General Hospital and the Primary Health care Clinics (PHCs). The survey was conducted over a period from 6 August to 25 December 2007. The subjects were Qatari nationals male and female aged below 16 years. The study is based on matching by age, gender and ethnicity of 170 cases with those of 170 controls. Face-to-face interviews were based on a questionnaire that included variables such as socio-demographic information, assessment of non-dietary covariates, assessment of dietary intake, vitamin D intake, type of feeding, clinical manifestations and laboratory investigations. Their health status was assessed by medical conditions, family history, BMI, past or present clinical manifestations, 25 (OH)D, Calcium, alkaline phosphatase, phosphorus, HbA1C, PTH, Mg and creatinine analysis. The study revealed that vitamin D deficiency was considerably higher in T1DM children (90.6%) compared to non-diabetic children (85.3%). There was a significant difference found in the mean value of vitamin D between T1DM and non-diabetic children (P = 0.009). There were statistically significant differences between type 1 diabetic and healthy subjects with respect to the occupation of parents (P < 0.001) and consanguinity rate (P < 0.047). Family history of vitamin D deficiency was considerably higher among T1DM children (35.3%) with a significant difference between diabetic and non-diabetic children (22.9) (P < 0.012). Vitamin D supplement with breast milk was very poor in diabetic children (37.4%) compared to non-diabetic children (47.7%). Majority of the studied subjects were breast-fed children (95.1% of diabetic children and 97.2% of healthy children). Multivariate logistic regression analysis revealed that fathers and mothers occupation, family history of DM, physical activity, low duration of time under sun light, breast feeding less than 6 months and low vitamin D level were considered as the main factors associated with the T1DM. In conclusion, the present study revealed that vitamin D deficiency was higher in T1DM children compared to non-diabetic. Moreover, vitamin D deficiency was common in Qatari young population. Vitamin D intake was very poor in children and it shows that supplementing infants with vitamin D might be a safe and effective strategy for reducing the risk of T1DM.

Impact of lifestyle and dietary habits on hypovitaminosis D in type 1 diabetes mellitus and healthy children from Qatar, a sun-rich country.

BACKGROUND: There are no population-based studies that have examined the association between vitamin D and type 1 diabetes mellitus (T1DM) and the role of lifestyle habits and dietary factors in young children in the Arabian Gulf and Middle East region. Little data on the intake of these nutrients in Mediterranean countries exist, and predictors of their suboptimal intake are not well defined. OBJECTIVE: The objective of this study was to determine the association between vitamin D status and T1DM and assess the impact of lifestyle and dietary habits on hypovitaminosis D in the young population of the State of Qatar. A matched case-control study was carried out among T1DM children and healthy subjects <16 years of age at the pediatric endocrinology outpatient clinics of the Hamad General Hospital and the primary health care clinics center. The survey was conducted over a period from 6 August to 25 December 2007. The sample included 170 cases and 170 controls matched by age, gender and ethnicity. METHODS: Face to face interviews were based on a questionnaire that included variables such as sociodemographic information, assessment of non-dietary covariates, assessment of dietary intake including vitamin D, type of feeding, clinical manifestations and laboratory investigations. Their health status was assessed by medical conditions, family history, body mass index, past or present clinical manifestations, serum 25(OH) vitamin D, calcium, alkaline phosphates, phosphorus, hemoglobin A1C, parathyroid hormone, magnesium and creatinine analysis. RESULTS: The study revealed that the incidence of severe vitamin D deficiency was considerably higher in T1DM (28.8%) compared with healthy children (17.1%). Although the mean serum level of vitamin D was significantly lower in T1DM children (15.80+/-9.23 ng/ml), compared with nondiabetic children (18.45+/-9.56 ng/ml), both groups belonged to the mild-moderate vitamin D deficiency category. A family history of vitamin D deficiency (35.3%; p=0.012) and diabetes mellitus (56.5%; p<0.001) was significantly higher in diabetic children. More than half of the diabetic (67.1%) and healthy children (51.2%) had no physical activity in their daily life. Both groups (65.9 vs. 62.9%) had very limited exposure to sunlight. Vitamin D supplement intake was very poor in diabetic children compared with healthy children; 60% of diabetic and 40.6% of healthy children never had any vitamin D supplement. The study revealed that vitamin D serum concentration, phosphorus, hemoglobin A1C, magnesium and creatinine show statistically significant differences between T1DM and healthy control subjects. A significant difference was noted between diabetic and healthy children for fractures (p=0.005), weakness (p=0.001) and gastroenteritis (p=0.025). CONCLUSIONS: The present study revealed that vitamin D deficiency is a common problem in Qatari children, but the incidence of vitamin D deficiency becomes very severe in T1DM children, compared with healthy children. This suggests that there is an association between vitamin D deficiency and T1DM. The data show that vitamin D status is dependent on sunshine exposure and dietary vitamin D intake. The results suggest the necessity of nutrition education to promote healthy eating habits among adolescents and their parents.