A nutrigenetic approach to examine the relationship between vitamin B12 status and metabolic traits in multiple ethnic groups

Low vitamin B12 concentrations have been shown to be risk factors for metabolic traits in numerous observational studies; however, the relationship has remained inconsistent. It is possible that certain genotypes might jointly contribute to obesity and vitamin B12 deficiency, and these may be modulated by lifestyle factors (dietary factors and physical activity levels) across different ethnic groups. The implementation of a genetic approach to establish the relationship between vitamin B12 and obesity could be a more desirable option over observational studies, as results are less prone to confounding factors. Hence, the main aims of this thesis were to examine for the first time the association of common vitamin B12-related single nucleotide polymorphisms (SNPs) and metabolic SNPs with vitamin B12 concentrations and metabolic outcomes in multiple ethnic groups. In addition, the interaction between these SNPs and dietary factors (protein, carbohydrate and fat) on vitamin B12 concentrations and metabolic traits was investigated. A total of five studies with different study designs were used. These studies included a case-control study (Chennai Urban Rural Study; CURES, Asian India, n=900), three cross-sectional cohort studies [Genetics of obesity and Diabetes study (GOOD study; Sinhalese Sri Lankan adults, n=109), The Minangkabau Indonesia Study on Nutrition and Genetics (MINANG study; Indonesian women; n=118) and Brazilian adolescents (n=113)] and a 16 week-dietary randomized, single-blind, parallel-group dietary intervention [Dietary Intervention and VAScular function (DIVAS study; British adults, n=119)]. Gene-diet interactions were observed in the Sri Lankan and Indonesian populations between the vitamin B12-related SNPs and protein energy intake (%) on markers of central obesity (waist circumference (P=0.002) and body fat percentage (P= 0.034), respectively). In the Brazilian adolescent population, the metabolic and vitamin B12 related SNPs showed a significant interaction with carbohydrate and protein intakes on oxidised low density lipoprotein cholesterol (P=0.005) and homocysteine concentrations (P = 0.007), respectively, which are well-known independent risk factors for cardiovascular disease. Additionally, in the Indonesian population, an interaction was observed between vitamin B12-related SNPs and dietary fibre intake (g) on glycated haemoglobin levels (P =0.042), a marker of long-term glycaemic status. Furthermore, for the first time, a novel association between two obesity-related SNPs and vitamin B12 concentrations (P = 0.018) was observed in the Indian population. In summary, these studies in multiple ethnic groups show that the relationship between B12 deficiency and metabolic outcomes may be influenced by dietary factors such as protein and fibre intake. However, in the Indian population, we found that vitamin B12 concentrations may be influenced by a genetic predisposition to obesity, but without a dietary influence. Given the limited sample size in some of the cohorts, replication of the study findings is highly warranted

The influence of one-carbon metabolism gene polymorphisms and gene-environment interactions on homocysteine, vitamin B12, folate and lipids in a Brazilian adolescent population

Background: Several single-nucleotide polymorphisms (SNPs) have been associated with the metabolism of Vitamin B12, folic acid, homocysteine and lipids. However, the interaction between SNPs involved in the one-carbon metabolism pathway and macronutrient intake on cardiovascular risk factors in the Brazilian population has not yet been investigated. Hence, the present study examined whether the association of ten SNPs involved in the one-carbon metabolism pathway with Vitamin B12, folic acid, homocysteine and lipid levels is modified by dietary factors and physical activity in adolescents with cardiovascular risk. Materials and Methods: A total of 113 adolescents (10–19 years old), from a public school in the city of Goiânia, Goiás, Brazil, underwent anthropometric, biochemical and food consumption evaluations and genetic tests. Results: After adjusting for potential confounders, SNPs rs4633 (catechol-O-methyltransferase, COMT), rs602662 (fucosyltransferase 2, FUT2) and rs1801394 (5-methyltetrahydrofolate-homocysteine methyltransferase reductase) showed significant associations with folic acid (P = 0.042), Vitamin B12 (P = 0.009) and oxidised low-density lipoprotein (ox-LDL) (P = 0.041) concentrations, respectively. The COMT SNP rs4680 showed a significant interaction with carbohydrate intake on ox-LDL concentrations (Pinteraction = 0.005). In addition, the FUT2 SNP rs602662 showed a significant interaction with protein intake on homocysteine concentrations (Pinteraction = 0.007). However, after correction for multiple testing, none of these associations and interactions were statistically significant. Conclusions: For the first time, we provide evidence for the interactions between COMT SNP rs4680 and carbohydrate intake on ox-LDL levels and the FUT2 SNP rs602662 and protein intake on homocysteine concentrations. However, replication of our results in a larger sample size is required to confirm our findings

Hubungan Tingkat Pendidikan dengan Tingkat Ketertarikan Masyarakat terhadap Pelayanan Gizi berbasis Gen di Indonesia

Latar Belakang: Penyakit Tidak Menular (PTM) merupakan salah satu penyebab kematian di dunia yang terus meningkat setiap tahunnya. Perkembangan ilmu Nutrigenetik dan pelayanan gizi berbasis gen memiliki peran dalam mencegah terjadinya PTM, tetapi masih banyak masyarakat yang tidak mengetahuinya. Tujuan: Untuk mengidentifikasi hubungan antara tingkat pendidikan dengan tingkat ketertarikan masyarakat terhadap pelayanan gizi berbasis gen di Indonesia. Metode: Desain penelitian cross-sectional dilakukan secara online menggunakan Qualtrics Survey pada Mei-Juni 2023 di DKI Jakarta, Jawa Barat, Jawa Tengah, Jawa Timur, dan DI Yogyakarta menggunakan teknik cluster sampling. Kuesioner sosiodemografi dan ketertarikan dibuat dan telah diuji validitas dan reliabilitasnya. Data statistik penelitian ini menggunakan uji chi-square. Hasil: Masyarakat memiliki tingkat ketertarikan yang tinggi terhadap adanya pelayanan gizi berbasisi gen di Indonesia (92,3%). Mayoritas responden setuju bahwa mereka akan menyarankan keluarga mereka untuk melakukan tes nutrigenetik (89,7%). Mereka setuju bahwa pelayanan gizi berbasis gen akan memberikan banyak manfaat bagi mereka (97,5%), serta sebagian besar responden menyatakan bersedia mengeluarkan biaya lebih untuk mendapatkan pelayanan gizi berbasis gen (62,4%). Sebagian besar responden tertarik melakukan tes nutrigenetik untuk mengetahui apakah mereka memiliki risiko penyakit atau tidak (95,9%). Namun, tidak terdapat hubungan antara tingkat pendidikan dengan tingkat ketertarikan masyarakat terhadap pelayanan gizi berbasis gen di Indonesia (p=0,134, OR:0,551, CI=95% (0,27 – 1,11)). Kesimpulan: Tinggi atau rendahnya pendidikan masyarakat Indonesia tidak berhubungan dengan ketertarikan terhadap pelayanan gizi berbasis gen. Tetapi, masyarakat tertarik dan setuju pelayanan gizi berbasis gen dapat memberikan banyak manfaat terutama untuk pencegahan PTM

Hubungan Tingkat Pengetahuan dan Minat Masyarakat Terhadap Pelayanan Gizi Berbasis Gen di Indonesia

Latar Belakang: Pesatnya perkembangan teknologi saat ini menciptakan pelayanan gizi berbasis gen sehingga terbentuknya inovasi baru dalam pelayanan gizi dapat membantu penurunan prevalensi Penyakit Tidak Menular (PTM). Namun, masyarakat saat ini masih belum banyak yang mengetahui tentang pelayanan gizi berbasis gen. Tujuan: Untuk mengetahui hubungan tingkat pengetahuan dan minat masyarakat terhadap pelayanan gizi berbasis gen di Indonesia. Metode: Desain penelitian ini adalah cross-sectional yang dilakukan secara online menggunakan Qualtrics Survey pada bulan Mei-Juni 2023. Teknik pengambilan sampel dalam penelitian ini menggunakan teknik cluster sampling lima Provinsi di Indonesia. Instrumen penelitian yang digunakan adalah kuesioner data karakteristik sosio-demografi, kuesioner terstruktur tentang pengetahuan dan minat masyarakat terhadap pelayanan gizi berbasi gen yang telah divalidasi. Analisis data statistik yang digunakan adalah uji Chi Square. Hasil: Diperoleh sebanyak 439 responden di lima wilayah provinsi di Indonesia. Mayoritas masyarakat memiliki tingkat pengetahuan rendah (51,7%) dan minat rendah (55,4%) terhadap pelayanan gizi berbasis gen di Indonesia. Terdapat hubungan yang signifikan antara pengetahuan dan minat mmasyarakat terhadap pelayanan gizi berbasis gen (p=0,029, OR=1,5, 95% CI=1,04-2,22). Kesimpulan: Terdapat hubungan antara tingkat pengetahuan dan minat masyarakat terhadap pelayanan gizi berbasis gen di Indonesia. Pelayanan gizi berbasis gen layak untuk dicoba sebagai salah satu alternatif dalam pencegahan PTM. Sebagian besar masyarakat Indonesia tidak mengetahui adanya layanan ini, media massa dapat digunakan untuk mengedukasi masyarakat tentang layanan nutrisi berbasis gen untuk nutrisi yang dipersonalisasi

Interaction between TCF7L2 polymorphism and dietary fat intake on high density lipoprotein cholesterol

Recent evidence suggests that lifestyle factors influence the association between the Melanocortin 4 receptor (MC4R) and Transcription Factor 7-Like 2 (TCF7L2) gene variants and cardio-metabolic traits in several populations; however, the available research is limited among the Asian Indian population. Hence, the present study examined whether the association between the MC4R single nucleotide polymorphism (SNP) (rs17782313) and two SNPs of the TCF7L2 gene (rs12255372 and rs7903146) and cardio-metabolic traits is modified by dietary factors and physical activity. This cross sectional study included a random sample of normal glucose tolerant (NGT) (n = 821) and participants with type 2 diabetes (T2D) (n = 861) recruited from the urban part of the Chennai Urban Rural Epidemiology Study (CURES). A validated food frequency questionnaire (FFQ) was used for dietary assessment and self-reported physical activity measures were collected. The threshold for significance was set at P = 0.00023 based on Bonferroni correction for multiple testing [(0.05/210 (3 SNPs x 14 outcomes x 5 lifestyle factors)]. After Bonferroni correction, there was a significant interaction between the TCF7L2 rs12255372 SNP and fat intake (g/day) (Pinteraction = 0.0001) on high-density lipoprotein cholesterol (HDL-C), where the 'T' allele carriers in the lowest tertile of total fat intake had higher HDL-C (P = 0.008) and those in the highest tertile (P = 0.017) had lower HDL-C compared to the GG homozygotes. In a secondary analysis of SNPs with the subtypes of fat, there was also a significant interaction between the SNP rs12255372 and polyunsaturated fatty acids (PUFA, g/day) (Pinteraction<0.0001) on HDL-C, where the minor allele carriers had higher HDL-C in the lowest PUFA tertile (P = 0.024) and those in the highest PUFA tertile had lower HDL-C (P = 0.028) than GG homozygotes. In addition, a significant interaction was also seen between TCF7L2 SNP rs12255372 and fibre intake (g/day) on HDL-C (Pinteraction<0.0001). None of the other interactions between the SNPs and lifestyle factors were statistically significant after correction for multiple testing. Our findings indicate that the association between TCF7L2 SNP rs12255372 and HDL-C may be modified by dietary fat intake in this Asian Indian population

A nutrigenetic approach for investigating the relationship between vitamin B12 status and metabolic traits in Indonesian women

Purpose: Adverse effects of maternal vitamin B12 deficiency have been linked to major clinical outcomes, including increased body mass index and gestational diabetes, however, less is known about vitamin B12 nutrition in non-pregnant women. Hence, the aim of the present study was to explore the relationships between metabolic traits and vitamin B12 status in a cohort of healthy Indonesian women and to investigate whether these relationships were modified by dietary intake using a genetic approach. Methods: A total of 117 Minangkabau women (aged 25-60 years), from the city of Padang, West Sumatra underwent anthropometric, biochemical, dietary intake analysis and genetic tests. Genetic risk scores (GRS) based on nine vitamin B12 associated single nucleotide polymorphisms (SNPs) (B12-GRS) and nine metabolic SNPs (metabolic-GRS) were constructed. Results: The B12-GRS and metabolic-GRS had no effect on vitamin B12 (P>0.160) and metabolic traits (P>0.085). However, an interaction was observed between the B12-GRS and dietary fibre intake (g) on glycated haemoglobin (HbA1C) levels (P interaction=0.042), where among those who consumed a low fibre diet (4.90 ± 1.00 g/day), individuals carrying ≥9 risk alleles for vitamin B12 deficiency had significantly higher HbA1C levels (P=0.025) compared to those carrying ≤8 risk alleles. Conclusion: Our study showed a significant impact of the B12-GRS on HbA1C concentrations through the influence of a dietary factor, however, our study failed to provide evidence for an impact of metabolic-GRS on lowering B12 concentrations. Further replication studies utilizing larger sample sizes are needed to confirm our findings

Peran Ahli Gizi Dalam Memberikan Pelayanan Gizi Berbasis Gen di Indonesia

Latar Belakang: Ilmu genetik berkembang sangat pesat memberikan dampak signifikan teradap suatu penyakit yang dapat dicegah dan dikelola oleh tenaga kesehatan professional, tetapi di Indonesia sendiri pengaplikasian dietetik masih belum banyak diketahui oleh karena itu ahli gizi perlu berperan dalam pengaplikasian nutritional genomics ini di dalam praktik kerja dietetik. Peran ahli gizi penting dalam memberikan informasi mengenai bagaimana gizi dan genetik berinteraksi dalam mempengaruhi Kesehatan dan memberikan alternatif intervensi gizi yang lebih dini. Tujuan: Mengetahui peran ahli gizi dalam memberikan pelayanan gizi berbasis gen di indonesia. Metode: Penelitian ini merupakan penelitian kualitatif dengan pendekatan fenomenologi, yang dilakukan di lima provinsi di Indonesia. Data informan di dapatkan dari penelitian kuantitatif, dengan teknik pengambilan informan yaitu purposive sampling dengan jumlah informan sebanyak enam orang. Pengumpulan data menggunakan structured interview dilaksanakan secara online dengan menggunakan Zoom Meeting. Analisis data yang digunakan yaitu analisis tematik dengan software NVIVO v.12. Hasil: Tenaga gizi yang sudah dan yang belum menerapkan pelayanan gizi berbasis gen ini sebagian besar sudah mengetahui terkait pelayanan gizi berbasis gen. Namun, sebagian dari mereka tidak mengetahui terkait definisi nutrigenetik dan nutrigenomik. sebagiannya mengetahui terkait peran tenaga gizi yaitu sebagai konselor untuk memberikan konseling, memberikan saran terkait pola makan yang sesuai dengan kebutuhan pasien, memberikan motivasi kepada pasien untuk menjalankan diet sesuai dengan kebutuhan pasien. Kesimpulan: Peran tenaga gizi dalam memberikan pelayanan gizi berbasis gen yaitu sebagai konselor untuk memberikan konseling, memberikan saran terkait pola makan yang sesuai dengan kebutuhan pasien, dan memberikan motivasi kepada pasien untuk menjalankan diet sesuai dengan kebutuhan pasien

Pandangan Ahli Gizi Tentang Pelayanan Gizi Berbasis Gen Di Indonesia

Latar Belakang: Penyakit kardiometabolik adalah penyebab utama kematian, morbiditas dan pengeluaran perawatan kesehatan polimorfisme nukleotida tunggal berhubungan dengan penyakit dan karakteristik kardiometabolik. Pandangan ahli gizi terhadap pelayanan gizi berbasis genetik memegang peranan penting dalam proses pencegahan dan penanganan dari penyakit-penyakit yang tidak menular tersebut (PTM). Tujuan: Mengetahui gambaran pandangan ahli gizi terhadap pelayanan gizi berbasis gen di Indonesia. Metode: Penelitian ini menggunakan metode penelitian kualitatif dengan pendekatan fenomenologi. Informan dalam penelitian ini adalah ahli gizi Indonesia yang berdomisili di lima provinsi besar yaitu DKI Jakarta, Jawa Barat, Jawa Tengah, Jawa Timur dan D.I Yogyakarta. Wawancara mendalam dilakukan terhadap enam informan. Teknik sampling yang digunakan purposive sampling tema penelitian adalah pandangan ahli gizi tentang pelayanan gizi berbasis gen sebagai pencegah PTM, pengetahuan ilmu genetik dan tes genetik. Analisis tematik dilakukan dalam menggunakan Nvivo v.12. Hasil: Pengetahuan ahli gizi terkait genetika dan pelayanan gizi berbasis gen sudah cukup baik, kemudian ahli gizi mengeluhkan biaya tes yang mahal untuk saat ini. Pengetahuan ahli gizi tentang pelayanan gizi berbasis gen sebagai pencegahan PTM sudah baik. Ahli gizi memahami apa itu PTM dan mereka mengaggap tes ini penting sebagai   pencegahan PTM. Kesimpulan: Ahli gizi memiliki pandangan bahwa pelayanan gizi berbasis gen itu penting untuk pencegahan PTM dan ahli gizi sudah cukup baik mengenai ilmu genetik. Ahli gizi perlu melaksanakan sosialisasi ke masyarakat tentang pentingnya keuntungan tes genetik untuk mencegah PTM agar banyak masyarakat yang berminat untuk melakukan pelayanan gizi berbasis gen

Exploring Knowledge of Gene-Based Nutrition Services Among Indonesian Nutritionists

Latar Belakang: Setiap individu memiliki jenis gen yang berbeda dan berpengaruh terhadap perbedaan risiko penyakit dan respon individu terhadap diet. Perkembangan ilmu nutritional genomics berakibat pada diketahuinya kerentanan penyakit dan dapat dicegah melalui pelayanan gizi berbasis gen. Pengetahuan pelayanan gizi berbasis gen penting bagi ahli gizi karena dapat memberikan informasi terkait gen dan diet. Tujuan: Untuk mengetahui gambaran pengetahuan ahli gizi tentang pelayanan gizi berbasis gen di Indonesia. Metode: Penelitian ini menggunakan desain penelitian kualitatif dengan pendekatan fenomenologi yang dilakukan di DKI Jakarta, Jawa Barat, Jawa Tengah, Jawa Timur, dan DI Yogyakarta. Teknik pengambilan sampel menggunakan purposive sampling dengan jumlah subjek sebanyak tujuh Ahli Gizi. Pengambilan data melalui wawancara mendalam secara offline dan online menggunakan Zoom Meeting. Hasil wawancara direkam dan dianalisis dengan teknik analisis tematik menggunakan software Nvivo 12.0. Hasil: Pengetahuan ahli gizi tentang ilmu nutritional genomics masih kurang. Ahli gizi bisa menjelaskan konsep dasar akan tetapi tidak mengetahui pengetahuan ini secara mendalam. Pengetahuan ahli gizi tentang pelayanan gizi berbasis gen juga masih terbatas, sehingga mereka masih meragukan peran mereka dalam pelayanan ini. Sedangkan pandangan ahli gizi terhadap pelayanan gizi berbasis gen umumnya positif dan menganggap pelayanan ini penting dan berharap instansi mereka bekerja dapat menyediakannya. Ahli gizi tertarik untuk memberikan pelayanan gizi berbasis gen dan bersemangat untuk belajar lebih lanjut mengenai ilmu nutritional genomics. Kesimpulan: Pengetahuan ahli gizi tentang pelayanan gizi berbasis gen masih kurang. Harapannya ahli gizi mendapat pelatihan, seminar, dan pemerataan pendidikan tentang ilmu nutritional genomics di perguruan tinggi untuk memenuhi kompetensi ahli gizi di masa depan

FTO gene-lifestyle interactions on serum adiponectin concentrations and central obesity in a Turkish population

The aim of the study was to investigate whether lifestyle factors modify the association fat mass and obesity-associated (FTO) gene single nucleotide polymorphisms (SNPs) and obesity in a Turkish population. The study included 400 unrelated individuals, aged 24-50 years recruited in a hospital setting. Dietary intake and physical activity were assessed using 24-hour dietary recall and self-report questionnaire, respectively. A genetic risk score (GRS) was developed using FTO SNPs, rs9939609 and rs10163409. Body mass index and fat mass index were significantly associated with FTO SNP rs9939609 (P=0.001 and P=0.002, respectively) and GRS (P=0.002 and P=0.003, respectively). The interactions between SNP rs9939609 and physical activity on adiponectin concentrations, and SNP rs10163409 and dietary protein intake on increased waist circumference were statistically significant (Pinteraction=0.027 and Pinteraction=0.044, respectively). This study demonstrated that the association between FTO SNPs and central obesity might be modified by lifestyle factors in this Turkish population